Memory controller and operating method thereof

ABSTRACT

A memory controller may include: a request checker identifying memory devices corresponding to requests received from a host among the plurality of memory devices and generating device information on the identified memory devices to perform operations corresponding to the requests; a dummy manager outputting a request for controlling a dummy pulse to be applied to channels of selected memory devices according to the device information among the plurality of channels; and a dummy pulse generator sequentially applying the dummy pulse to the channels coupled to the selected memory devices, based on the request for controlling the dummy pulse. A memory controller may include an idle time monitor outputting an idle time interval of the memory device and a clock signal generator generating a clock signal based on the idle time interval and outputting the clock signal to the memory device through the channel to perform a current operation.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is division of U.S. application Ser. No.16/888,444 filed May 29, 2020, which is a continuation in part of U.S.application Ser. No. 16/841,030 filed on Apr. 6, 2020, now U.S. Pat. No.11,264,086, U.S. application Ser. No. 16/868,116 filed on May 6, 2020,now U.S. Pat. No. 11,355,213, and U.S. application Ser. No. 16/730,826filed on Dec. 30, 2019, now U.S. Pat. No. 11,257,530, which respectivelyclaim priority under 35 U.S.C. § 119(a) to Korean patent applicationnumber 10-2019-0108259, filed on Sep. 2, 2019, Korean Patent ApplicationNo. 10-2020-0011548, filed on Jan. 31, 2020, and Korean PatentApplication Number 10-2019-0149055, filed on Nov. 19, 2019, each ofwhich is incorporated herein by reference in its entirety.

BACKGROUND Field of Invention

The present disclosure generally relates to an electronic device, andmore particularly, to a memory controller and an operating methodthereof.

Description of Related Art

A storage device stores data under the control of a host device such asa computer, a smart phone or a smart pad. The storage device may be atype that stores data on a magnetic disk, such as a Hard Disk Drive(HDD), or of a type that stores data on a semiconductor memory, i.e., anonvolatile memory, such as a Solid State Drive (SSD) or a memory card.

The storage device may include a memory device that stores data and amemory controller that controls the memory device. The memory device maybe a volatile memory device or a nonvolatile memory device. Thenonvolatile memory device may be any of a Read Only Memory (ROM), aProgrammable ROM (PROM), an Electrically Programmable ROM (EPROM), anElectrically Erasable and Programmable ROM (EEPROM), a flash memory, aPhase-change RAM (PRAM), a Magnetic RAM (MRAM), a Resistive RAM (RRAM),and/or a Ferroelectric RAM (FRAM).

SUMMARY

Embodiments relate to a memory controller gradually changing a totalcurrent consumed by a plurality of memory devices, and an operatingmethod of the memory controller. In an embodiment, the memory controllermay control the plurality of memory devices using a dummy pulsesequentially applied to a plurality of channels coupled to the pluralityof memory devices. In an embodiment, the memory controller may generatea clock signal based on an initial frequency that is lower than a normalfrequency and control the plurality of memory devices using the clocksignal. As a result, the memory controller may prevent a sudden changein the total current consumption by the plurality of memory devices.

Embodiments provide a memory controller capable of sequentiallyincreasing or decreasing a total current consumed by a plurality ofmemory devices, and an operating method of the memory controller. In anembodiment, the memory controller may sequentially apply a dummy pulseto a plurality of channels coupled to the plurality of memory devices tosequentially increase the total current consumed by the plurality ofmemory devices, or sequentially interrupt the dummy pulse applied to theplurality of channels to sequentially decrease the total current, orboth. As a result, noise in a voltage source due to a sudden change intotal current consumption in the plurality of memory devices may besubstantially prevented.

In accordance with an embodiment of the present disclosure, a memorycontroller for controlling a plurality of memory devices coupled througha plurality of channels includes a request checker configured toidentify memory devices corresponding to requests received from a hostamong the plurality of memory devices, and generate device informationon the identified memory devices to perform operations corresponding tothe requests, a dummy manager configured to output a request forcontrolling a dummy pulse to be applied to channels of memory devicesselected according to the device information among the plurality ofchannels, and a dummy pulse generator configured to sequentially applythe dummy pulse to the channels coupled to the selected memory devicesbased on the request for controlling the dummy pulse.

Embodiments of the present disclosure relate to a memory controllergenerating a clock signal to be output to one or more of a plurality ofmemory devices based on an initial frequency during an initial frequencyscaling period, when an idle time exceeds a threshold time. Because theinitial frequency of the clock signal is less than a normal frequency,total current consumption in a storage device including the plurality ofmemory devices may be prevented from rapidly increasing when theplurality of memory devices start operations simultaneously. As aresult, noise in a voltage source due to a sudden increase in the totalcurrent consumption may be substantially prevented.

In accordance with an embodiment of the present disclosure, a memorycontroller is configured to control a memory device and the memorydevice is coupled to the memory controller through a channel. The memorycontroller includes an idle time monitor configured to output an idletime interval of the memory device, and a clock signal generatorconfigured to generate a clock signal based on the idle time intervaland output the clock signal to the memory device through the channel toperform a current operation. The idle time interval is between an endtime of a previous operation of the memory device and a start time ofthe current operation.

Embodiments of the present disclosure relate to a memory systemperforming a modulation operation on a clock signal to generate amodulation clock signal that includes a plurality of modulationsections, thereby indexing read data into a plurality of section datathat respectively correspond to the plurality of modulation sections ofthe clock signal. When specific section data of the read data includesone or more abnormal bits, the specific section data may be re-read froma memory cell region, rather than re-reading the entire read data,thereby increasing the efficiency of performing a read operationcompared to a conventional memory system.

In accordance with an embodiment of the present disclosure, a memorysystem includes a memory device including a memory cell region forstoring data and a memory controller. The memory device loops back afirst clock to generate a second clock and outputs read data that areread from the memory cell region in synchronization with the secondclock. The memory controller generates the first clock that includes aplurality of modulation sections by performing a modulation operation ona source clock according to a specific scheme, outputs the first clockto the memory device, and receives the read data in response to thesecond clock. The read data includes a plurality of section datacorresponding to the plurality of modulation sections included in thesecond clock, respectively, and the memory controller verifiesreliability of each of the plurality of section data included in theread data by performing a demodulation operation on the second clockaccording to the specific scheme.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are described more fully below with reference to theaccompanying drawings; however, embodiments of the present disclosuremay be implemented in different forms and thus should not be construedas limited to the embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure is thorough andcomplete and fully conveys the scope of the embodiments to those skilledin the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.Like reference numerals refer to like elements throughout. Also,throughout the specification, reference to “an embodiment,” “anotherembodiment” or the like is not necessarily to only one embodiment, anddifferent references to any such phrase are not necessarily to the sameembodiment(s).

FIG. 1 is a block diagram illustrating a storage device in accordancewith an embodiment of the present disclosure.

FIG. 2 is a block diagram illustrating the storage device shown in FIG.1 in accordance with an embodiment of the present disclosure.

FIG. 3 is a diagram illustrating a structure of a memory device, such asthat shown in FIG. 1.

FIG. 4 is a diagram illustrating a memory block.

FIG. 5 is a diagram illustrating an embodiment of memory devices coupledto a plurality of channels.

FIG. 6 is a diagram illustrating another embodiment of memory devicescoupled to the plurality of channels.

FIG. 7 is a diagram illustrating a change in total current consumptionand noise of a voltage source, when memory devices coupled to aplurality of channels simultaneously start or end operations.

FIG. 8 is a diagram illustrating a change in total current consumptionand noise of a voltage source, when a plurality of memory devicessimultaneously end operations while performing the operations.

FIG. 9 is a diagram illustrating a structure of a memory controller,such as that shown in FIG. 2, which applies a dummy pulse for eachchannel.

FIG. 10 is a diagram illustrating a method for sequentially increasingand decreasing a total current consumption.

FIG. 11 is a diagram illustrating another embodiment of sequentiallyincreasing and decreasing a total current consumption.

FIG. 12 is a diagram illustrating a structure of the memory controllershown in FIG. 2, which sequentially decreases a total currentconsumption.

FIG. 13 is a diagram illustrating application or interruption of a dummypulse, which is determined based on a command queue.

FIG. 14 is a diagram illustrating a dummy pulse output based on a chipenable signal.

FIG. 15 is a diagram illustrating an operation of the memory controllerin accordance with an embodiment of the present disclosure.

FIG. 16 is a diagram illustrating an operation of the memory controllerin accordance with an embodiment of the present disclosure.

FIG. 17 is a diagram illustrating an operation of the memory controllerin accordance with an embodiment of the present disclosure.

FIG. 18 is a diagram illustrating an operation of the memory controllerin accordance with an embodiment of the present disclosure.

FIG. 19 is a diagram illustrating the memory cell array of FIG. 3 inaccordance with an embodiment of the present disclosure.

FIG. 20 is a circuit diagram illustrating a memory block of the memoryblocks of FIG. 3 in accordance with an embodiment.

FIG. 21 is a circuit diagram illustrating a memory block of the memoryblocks of FIG. 3 in accordance with an embodiment.

FIG. 22 is a circuit diagram illustrating a memory block of the memoryblocks included in the memory cell array of FIG. 3 in accordance with anembodiment.

FIG. 23 is a diagram illustrating signals which are exchanged between amemory controller and a memory device in accordance with an embodiment.

FIG. 24 is a diagram for describing a change in entire currentconsumption when memory devices coupled to a plurality of channels startoperations substantially at the same time in accordance with anembodiment.

FIG. 25 is a block diagram illustrating a memory controller inaccordance with an embodiment of the present disclosure.

FIG. 26 is a block diagram illustrating a clock signal generator of FIG.25 in accordance with an embodiment.

FIG. 27 is a flowchart for describing a method of operating a memorycontroller in accordance with an embodiment of the present disclosure.

FIGS. 28A and 28B are timing diagrams for describing a method ofoperating a memory controller in accordance with an embodiment of thepresent disclosure.

FIG. 29 is a flowchart illustrating step S140 of FIG. 27 in accordancewith an embodiment of the present disclosure.

FIGS. 30A and 30B are timing diagrams for describing the embodimentillustrated in FIG. 29.

FIG. 31 is a flowchart illustrating step S140 of FIG. 27 in accordancewith an embodiment of the present disclosure.

FIG. 32 is a timing diagram for describing the embodiment illustrated inFIG. 31.

FIG. 33 is a flowchart illustrating step S140 of FIG. 27 in accordancewith an embodiment of the present disclosure.

FIG. 34 is a timing diagram for describing the embodiment illustrated inFIG. 33.

FIG. 35 is a flowchart illustrating a method of operating a memorycontroller in accordance with an embodiment of the present disclosure.

FIG. 36 is a diagram for describing a method of determining an idle timeaccording to steps S410 and S420 of FIG. 35 in accordance with anembodiment of the present disclosure.

FIG. 37 is a flowchart illustrating a method of operating the memorycontroller in accordance with an embodiment of the present disclosure.

FIG. 38 is a diagram for describing a method of determining an idle timeaccording to steps S510 and S520 of FIG. 37 in accordance with anembodiment of the present disclosure.

FIG. 39 is a diagram illustrating another embodiment of a memorycontroller, such as that shown in FIG. 1.

FIG. 40 is a block diagram illustrating a Solid State Drive (SSD) systemto which the storage device is applied in accordance with an embodimentof the present disclosure.

FIG. 41 is a block diagram illustrating a user system to which thestorage device is applied in accordance with an embodiment of thepresent disclosure.

FIG. 42 is a block diagram illustrating a data processing systemincluding a memory system in accordance with an embodiment of thepresent disclosure.

FIG. 43 is a block diagram illustrating an operation of a memory systemin accordance with an embodiment of the present disclosure.

FIG. 44 is a block diagram illustrating an operation of a memory systemin accordance with an embodiment of the present disclosure.

FIG. 45 is a block diagram illustrating an operation of a memory systemin accordance with an embodiment of the present disclosure.

FIGS. 46 and 47 are waveform diagrams illustrating a clock modulationoperation used in a memory system in accordance with an embodiment ofthe present disclosure.

DETAILED DESCRIPTION

The specific structural and functional description disclosed herein ismerely for the purpose of describing embodiments according toembodiments of the present disclosure. Embodiments of the presentdisclosure, however, may be implemented in various forms, and thus isnot limited to the embodiments set forth herein.

Various embodiments of the present disclosure are described in detailbelow with reference to the accompanying drawings in order for thoseskilled in the art to be able to readily implement and practiceembodiments of the present disclosure.

FIG. 1 is a block diagram illustrating a storage device according to anembodiment of the present disclosure.

Referring to FIG. 1, the storage device 50 may include a memory device100 and a memory controller 200.

The storage device 50 may be for storing data under the control of ahost 300, such as a mobile phone, a smart phone, an MP3 player, a laptopcomputer, a desktop computer, a game console, a TV, a tablet PC or anin-vehicle infotainment.

The storage device 50 may be configured as any of various types ofstorage devices according to a host interface that is a communicationscheme with the host 300. For example, the storage device 50 may beimplemented as a Solid State Drive (SSD), a Multi-Media Card (MMC), anEmbedded MMC (eMMC), a Reduced Size MMC (RS-MMC), a micro-MMC(micro-MMC), a Secure Digital (SD) card, a mini-SD card, a micro-SDcard, a Universal Serial Bus (USB) storage device, a Universal FlashStorage (UFS) device, a Compact Flash (CF) card, a Smart Media Card(SMC), and/or a memory stick.

The storage device 50 may be manufactured as any of various kinds ofpackage types. For example, the storage device 50 may be manufactured asa Package-On-Package (POP), a System-In-Package (SIP), a System-On-Chip(SOC), a Multi-Chip Package (MCP), a Chip-On-Board (COB), a Wafer-levelFabricated Package (WFP), and/or a Wafer-level Stack Package (WSP).

The memory device 100 may store data. The memory device 100 operatesunder the control of the memory controller 200. The memory device 100may include a memory cell array including a plurality of memory cellsfor storing data. The memory cell array may include a plurality ofmemory blocks. Each memory block may include a plurality of memorycells, which may constitute a plurality of pages. In an embodiment, thepage may be a unit for storing data in the memory device 100 or readingdata stored in the memory device 100. The memory block may be a unit forerasing data.

In an embodiment, the memory device 100 may be a Double Data RateSynchronous Dynamic Random Access Memory (DDR SDRAM), a Low Power DoubleData Rate 4 (LPDDR4) SDRAM, a Graphics Double Data Rate (GDDR) SRAM, aLow Power DDR (LPDDR), a Rambus Dynamic Random Access Memory (RDRAM), aNAND flash memory, a vertical NAND flash memory, a NOR flash memory, aResistive Random Access Memory (RRAM), a Phase-Change Random AccessMemory (PRAM), a Magnetoresistive Random Access Memory (MRAM), aFerroelectric Random Access Memory (FRAM), a Spin Transfer Torque RandomAccess Memory (STT-RAM), or the like. In this specification, by way ofexample, features and aspects of embodiments of the present disclosureare described in the context in which the memory device 100 is a NANDflash memory.

In an embodiment, the memory device 100 may be implemented in atwo-dimensional array structure or three-dimensional array structure.Below, an example in which the memory device 100 is implemented in thethree-dimensional array structure is described as an embodiment;however, the present disclosure is not limited to the three-dimensionalarray structure. The present disclosure may be applied to not only aflash memory device in which a charge storage layer is configured with aFloating Gate (FG) but also a Charge Trap Flash (CTF) in which a chargestorage layer is configured with an insulating layer.

In an embodiment, the memory device 100 may be operated using a SingleLevel Cell (SLC) scheme in which one data bit is stored in one memorycell. Alternatively, the memory device 100 may be operated using ascheme in which at least two data bits are stored in one memory cell.For example, the memory device 100 may be operated using a Multi-LevelCell (MLC) scheme in which two data bits are stored in one memory cell,a Triple Level Cell (TLC) scheme in which three data bits are stored inone memory cell, or a Quadruple Level Cell (QLC) scheme in which fourdata bits are stored in one memory cell.

The memory device 100 is configured to receive a command and an addressfrom the memory controller 200 and access an area selected by theaddress in the memory cell array. That is, the memory device 100 mayperform an operation corresponding to the command on the area selectedby the address. For example, the memory device 100 may perform a write(program) operation, a read operation, and an erase operation accordingto the received command. For example, when a program command isreceived, the memory device 100 may program data in the area selected bythe address. When a read command is received, the memory device 100 mayread data from the area selected by the address. When an erase commandis received, the memory device 100 may erase data stored in the areaselected by the address.

In an embodiment, multiple instances of the memory device 100 may beprovided. That is, a plurality of memory devices may be included in thestorage device 50.

The plurality of memory devices may be coupled to, for communicationwith, the memory controller 200 through channels CH. For example, thememory controller 200 may instruct an operation of each of the pluralityof memory devices, and each of the plurality of memory devices mayperform an operation corresponding to the instruction of the memorycontroller 200. Also, each of the plurality of memory devices may outputa result obtained by performing the operation to the memory controller200.

The memory controller 200 may control overall operations of the storagedevice 50.

When a power supply voltage is applied to the storage device 50, thememory controller 200 may execute firmware (FW). In the case where thememory device 100 is a flash memory device, the memory controller 200may execute firmware such as a flash translation layer (FTL) forcontrolling communication between the host 300 and the memory device100.

In an embodiment, the memory controller 200 may include firmware whichreceives data and a logical block address (LBA) from the host 300, andtranslates the LBA into a physical block address (PBA) indicatingaddresses of memory cells in which data is to be stored, the memorycells being included in the memory device 100. The memory controller 200may store, in a buffer memory, a logical-physical address mapping tableindicating mapping relationship between logical block addresses LBA andphysical block addresses PBA.

The memory controller 200 may control the memory device 100 to perform aprogram operation, a read operation, or an erase operation in responseto a request from the host 300. For example, if a program request isreceived from the host 300, the memory controller 200 may change theprogram request into a program command, and provide the program command,a PBA, and data to the memory device 100. If a read request along withan LBA is received from the host 300, the memory controller 200 maychange a read request into a read command, select a PBA corresponding tothe LBA, and provide the read command and the PBA to the memory device100. If an erase request along with an LBA is received from the host300, the memory controller 200 may change the erase request into anerase command, select a PBA corresponding to the LBA, and provide theerase command and the PBA to the memory device 100.

In an embodiment, the memory controller 200 may autonomously generate aprogram command, an address, and data without a request from the host300, and transmit them to the memory device 100. For example, the memorycontroller 200 may provide a command, an address, and data to the memorydevice 100 to perform background operations such as a program operationfor wear leveling, and a program operation for garbage collection.

In an embodiment, the storage device 50 may further include a buffermemory (not illustrated). The memory controller 200 may control dataexchange between the host 300 and the buffer memory (not illustrated).Alternatively, the memory controller 200 may temporarily store systemdata for controlling the memory device 100 in the buffer memory. Forexample, the memory controller 200 may temporarily store data input fromthe host 300 in the buffer memory, and thereafter transmit the datatemporarily stored in the buffer memory to the memory device 100.

In various embodiments, the buffer memory may be used as an operatingmemory or a cache memory of the memory controller 200. The buffer memorymay store codes or commands to be executed by the memory controller 200.Alternatively, the buffer memory may store data to be processed by thememory controller 200.

In an embodiment, the buffer memory may be embodied using an SRAM or aDRAM such as a double data rate synchronous dynamic random access memory(DDR SDRAM), a DDR4 SDRAM, a low power double data rate4 (LPDDR4) SDRAM,a graphics double data rate (GDDR) SDRAM, a low power DDR (LPDDR), or arambus dynamic random access memory (RDRAM).

In various embodiments, the buffer memory may be provided outside thestorage device 50. In this case, volatile memory devices providedoutside the storage device 50 may function as the buffer memory.

In an embodiment, the memory controller 200 may control at least two ormore memory devices. In this case, the memory controller 200 may controlthe memory devices in an interleaving manner so as to enhance theoperating performance.

The host 300 may communicate with the storage device 50 using at leastone of various communication methods such as universal serial bus (USB),serial AT attachment (SATA), serial attached SCSI (SAS), high speedinterchip (HSIC), small computer system interface (SCSI), peripheralcomponent interconnection (PCI), PCI express (PCIe), nonvolatile memoryexpress (NVMe), universal flash storage (UFS), secure digital (SD),multi-media card (MMC), embedded MMC (eMMC), dual in-line memory module(DIMM), registered DIMM (RDIMM), and load reduced DIMM (LRDIMM)communication methods.

FIG. 2 is a block diagram illustrating a storage device according to anembodiment of the present disclosure. For example, the storage device 50shown in FIG. 2 may be suitable for use as the storage device 50 shownin FIG. 1 and overlapping descriptions may be omitted for the interestof brevity.

The memory controller 200 may include a request checker 210. The requestchecker 210 may receive a request from the host 300, and may check whichmemory device among the plurality of memory devices the received requestis directed to. The request checker 210 may generate device informationby checking a memory device on which an operation corresponding to therequest received from the host 300 is to be performed, based on therequest. The device information may identify the memory device on whichthe operation is to be performed.

When operations are simultaneously performed or ended in memory devices,total current consumption of the storage device is rapidly increased ordecreased, and hence noise may occur in a voltage source. Therefore, inorder to prevent noise from occurring in the voltage source, operationsto be performed on the memory devices may be delayed, or a dummy pulsemay be applied to the memory devices, before the operations areperformed on the memory devices.

Therefore, operations corresponding to requests received from the host300 may be delayed and performed at a later time. That is, when therequests received from the host 300 allow operations to besimultaneously performed, the operations may be performed in a manner inwhich a next memory device performs an operation when another of thememory devices completes an operation.

However, when the operations corresponding to the requests received fromthe host 300 are delayed and performed later, a program time islengthened, and therefore, program performance may be decreased. Thatis, latency corresponding to the delayed time may occur.

Accordingly, in an embodiment of the present disclosure, a method forapplying a dummy pulse to a plurality of memory devices beforeoperations are performed on the plurality of memory devices is provided.

In accordance with an embodiment of the present disclosure, the memorydevices do not delay and perform operations, but simultaneously performthe operations after a dummy pulse is applied to memory devices on whichthe operations are to be performed, so that fast transmission of dataand/or fast transfer of signals is possible.

In an embodiment, before operations are performed on memory devicesidentified in device information, a dummy pulse may be applied to achannel coupled to each of the corresponding memory devices. A dummypulse is not simultaneously applied to a plurality of channels, but maybe sequentially applied to each channel. That is, after the dummy pulseis applied to one channel of the plurality of channels, the dummy pulsemay be applied to another channel whenever a set time elapses.

The memory controller 200 may include a dummy manager 220. The dummymanager 220 may output a request for applying or interrupting a dummypulse.

Specifically, when it is determined that a plurality of memory devicessimultaneously start operations, the dummy manager 220 may output adummy pulse generation request, based on device information. That is,the dummy manager 220 may output a request for sequentially generatingand applying a dummy pulse to channels to which memory devices includedin the device information are coupled. For example, the dummy manager220 may request the dummy pulse to be applied to a second channel aftera certain time elapses from when the dummy pulse is applied to a firstchannel. Moreover, right after operations are performed, the dummymanager 220 may determine interrupting the applying a dummy pulse.Namely, since the memory devices start to operate, the dummy pulse nolonger needs to be generated for increasing the total currentconsumption progressively.

Also, when it is determined that a plurality of memory devicessimultaneously suspend or end operations, the dummy manager 220 mayoutput a dummy pulse generation request or dummy pulse interruptionrequest, based on a chip enable signal and a command queue level.

Specifically, at least one memory device of the plurality of memorydevices may suspend an operation. Whether the memory device suspends theoperation may be determined based on a high-state chip enable signalreceived from an enable signal generator 240. For example, the enablesignal generator 240 may output a low-state chip enable signal to aselected memory device, and output high-state chip enable signal tomemory devices in which operations are all ended or which are unselectedmemory devices.

The dummy manager 220 may receive a command queue level of a memorydevice corresponding to the high-state chip enable signal. The commandqueue level may be determined according to a number of commands queuedin a command queue. When a command queue level is not 0, the dummymanager 220 may request the dummy pulse to be applied to a channelcoupled to a memory device corresponding to the corresponding commandqueue level.

In order to prevent a plurality of memory devices from simultaneouslysuspending operations, the dummy manager 220 may apply the dummy pulseto channels coupled to the plurality of memory devices and thensequentially interrupt the applied dummy pulse. For example, when memorydevices coupled to first to third channels suspend operations, the dummymanager 220 may request the dummy pulse to be applied to the first tothird channels and then request the application of the dummy pulse to besequentially suspended from the first channel.

The memory controller 200 may include a dummy pulse generator 230. Thedummy pulse generator 230 may be a toggle transmitter that generates adummy toggle and transmits the generated dummy toggle to a memorydevice. The dummy toggle may represent a set of dummy pulses to beapplied to the channels. The toggle transmitter may generate the dummytoggle in one or more channels in addition to a channel for transmittingdata. The toggle transmitter may generate the dummy toggle before datais transmitted.

The toggle transmitter may generate the dummy toggle, based on a warm-upenable signal generated on the basis of a request received from the host300. The warm-up enable signal may identify a number of channels coupledto memory devices on which operations are to be performed in response tothe request received from the host 300.

In an embodiment, the toggle transmitter may sequentially increase acurrent flowing through input/output pins coupled thereto, orsequentially apply the dummy toggle to the input/output pins to increasethe number of input/output pins to which the dummy toggle is appliedamong the input/output pins.

In an embodiment, the dummy pulse generator 230 may generate orinterrupt the dummy pulse by receiving the dummy pulse generationrequest or dummy pulse interruption request from the dummy manager 220.

For example, when the dummy pulse generator 230 receives the dummy pulsegeneration request, the dummy pulse generator 230 may generate the dummypulse to be applied to a plurality of channels. Also, when the dummypulse generator 230 receives the dummy pulse interruption request, thedummy pulse generator 230 may interrupt the dummy pulse applied to theplurality of channels by suspending the generation of the dummy pulse.The plurality of channels to which the dummy pulse is applied or fromwhich the dummy pulse is interrupted may be channels except channels fortransmitting data corresponding to requests received from the host.

In an embodiment, when a plurality of memory devices simultaneouslystart operations, the dummy pulse generator 230 may generate the dummypulse to be sequentially applied to a plurality of channels. The dummypulse generator 230 may adjust a degree to which a total currentconsumption of the plurality of memory devices is increased, by settinga period of the dummy pulse, a level of the dummy pulse, or a time forwhich the dummy pulse is applied.

In an embodiment, when a plurality of memory devices simultaneously endoperations, the dummy pulse generator 230 may generate the dummy pulseto be applied to channels to which the memory devices ending theoperations are coupled and then sequentially interrupt the dummy pulse.Similarly, the dummy pulse generator 230 may adjust a degree to which atotal current consumption of the plurality of memory devices isdecreased, by setting a period of the dummy pulse, a level of the dummypulse, or a duration of the dummy pulse.

The memory controller 200 may include the enable signal generator 240.The enable signal generator 240 may generate signals for controlling aselected memory device 100 according to an address, and transmit thegenerated signals through control signal lines coupled to the selectedmemory device 100. The control signal lines may include a chip enableline CE #, a write enable line WE #, a read enable line RE #, an addresslatch enable line ALE, a command latch enable line CLE, a writeprevention line WP #, and a ready/busy line RB.

For example, the enable signal generator 240 may generate a chip enablesignal input through the chip enable line CE #, a write enable signalinput through the write enable line WE #, a read enable signal inputthrough the read enable line RE #, an address latch enable signal inputthrough the address latch enable line ALE, a command latch enable signalinput through the command latch enable line CLE, and a write preventionsignal input through the write prevention line WP #.

In an embodiment, the chip enable signal generated by the enable signalgenerator 240 may be a signal that enables communication between thememory controller 200 and the memory device 100. For example, when thechip enable signal is in a low state, the communication between thememory controller 200 and the memory device 100 is enabled. When thechip enable signal is in a high state, the communication between thememory controller 200 and the memory device 100 is disabled.

The enable signal generator 240 may generate the chip enable signal tobe provided to the memory device 100 and the dummy manager 220. Thememory device 100 may communicate with the memory controller 200 byreceiving the chip enable signal, and the dummy manager 220 maydetermine whether the dummy pulse is applied to channels coupled to aplurality of memory devices, by receiving the chip enable signal.

The memory controller 200 may include a command queue group 250. Thecommand queue group 250 may include command queues respectivelycorresponding to a plurality of memory devices.

For example, the number of command queues in the command queue group 250may correspond to the number of the memory devices. Therefore, commandsexecuted in each of the plurality of memory devices may be queued in thecorresponding command queue. The command queue group 250 may output anumber of commands queued in a command queue for a corresponding memorydevice in response to a request from the dummy manager 220. The numberof commands queued in each command queue may be a command queue level.For example, when a number of commands queued in a command queuecorresponding to one memory device is “0,” the command queue level ofthe corresponding memory device may be “0.” When a number of commandsqueued in a command queue corresponding to one memory device is “1,” thecommand queue level of the corresponding memory device may be “1.”

In an embodiment, a channel to which the dummy pulse is applied may bedetermined based on the command queue level. That is, although thememory device 100 temporarily ends an operation, when a memory device isto immediately perform another operation, the dummy pulse may be appliedto a channel coupled to the corresponding memory device.

The memory controller 200 may include a data transmitter (not shown).The data transmitter may transmit data through channels corresponding torequests received from the host. For example, when a request receivedfrom the host is a program request for a first memory device among aplurality of memory devices, the data transmitter may transmit datathrough a first channel coupled to the first memory device. The channelthrough which the data is transmitted may be different from the channelthrough which the dummy pulse is applied or interrupted.

FIG. 3 is a diagram illustrating a structure of the memory device shownin FIG. 1.

Referring to FIG. 3, the memory device 100 may include a memory cellarray 110, a peripheral circuit 120, and control logic 130.

The memory cell array 110 includes a plurality of memory blocks BLK1 toBLKz. The plurality of memory blocks BLK1 to BLKz are coupled to a rowdecoder 121 through row lines RL. The plurality of memory blocks BLK1 toBLKz are coupled to a page buffer group 123 through bit lines BL1 toBLn. Each of the plurality of memory blocks BLK1 to BLKz includes aplurality of memory cells. In an embodiment, the plurality of memorycells may be nonvolatile memory cells. Memory cells coupled to the sameword line may be defined as one page. Therefore, one memory block mayinclude a plurality of pages.

The row lines RL may include at least one source select line, aplurality of word lines, and at least one drain select line.

Each of the memory cells included in the memory cell array 110 may beconfigured as a Single Level Cell (SLC) storing one data bit, aMulti-Level Cell (MLC) storing two data bits, a Triple Level Cell (TLC)storing three data bits, or a Quadruple Level Cell (QLC) storing fourdata bits.

The peripheral circuit 120 may perform a program operation, a readoperation or an erase operation on a selected region of the memory cellarray 110 under the control of the control logic 130. The peripheralcircuit 120 may drive the memory cell array 110. For example, theperipheral circuit 120 may apply various operating voltages to the rowlines RL and the bit lines BL1 to BLn, or discharge the applied voltagesunder the control of the control logic 130.

The peripheral circuit 120 may include the row decoder 121, the voltagegenerator 122, the page buffer group 123, a column decoder 124, aninput/output circuit 125, and a sensing circuit 126.

The row decoder 121 is coupled to the memory cell array 110 through therow lines RL. The row lines RL may include at least one source selectline, a plurality of word lines, and at least one drain select line. Inan embodiment, the word lines may include normal word lines and dummyword lines. In an embodiment, the row lines RL may further include apipe select line.

The row decoder 121 decodes a row address RADD received from the controllogic 130. The row decoder 121 selects at least one memory block amongthe memory blocks BLK1 to BLKz according to the decoded address. Also,the row decoder 121 may select at least one word line of the selectedmemory block to apply voltages generated by the voltage generator 122 tothe at least one word line WL according the decoded address.

For example, in a program operation, the row decoder 121 may apply aprogram voltage to the selected word line, and apply a program passvoltage having a level lower than that of the program voltage tounselected word lines. In a program verify operation, the row decoder121 may apply a verify voltage to the selected word line, and apply averify pass voltage having a level higher than that of the verifyvoltage to the unselected word lines.

In a read operation, the row decoder 121 may apply a read voltage to theselected word line, and apply a read pass voltage having a level higherthan that of the read voltage to the unselected word lines.

In an embodiment, an erase operation of the memory device 100 isperformed in a memory block unit. In the erase operation, the rowdecoder 121 may select one memory block according to the decodedaddress. In the erase operation, the row decoder 121 may apply a groundvoltage to word lines coupled to the selected memory blocks.

The voltage generator 122 operates under the control of the controllogic 130. The voltage generator 122 generates a plurality of voltagesby using an external power voltage supplied to the memory device 100.Specifically, the voltage generator 122 may generate various operatingvoltages Vop used in program, read, and erase operations in response toan operation signal OPSIG. For example, the voltage generator 122 maygenerate a program voltage, a verify voltage, a pass voltage, a readvoltage, an erase voltage, and the like under the control of the controllogic 130.

In an embodiment, the voltage generator 122 may generate an internalpower voltage by regulating the external power voltage. The internalpower voltage generated by the voltage generator 122 is used as anoperation voltage for the memory device 100.

In an embodiment, the voltage generator 122 may generate a plurality ofvoltages by using the external power voltage or the internal powervoltage.

For example, the voltage generator 122 may include a plurality ofpumping capacitors for receiving the internal power voltage, andgenerate the plurality of voltages by selectively activating theplurality of pumping capacitors under the control of the control logic130.

The plurality of generated voltages may be supplied to the memory cellarray 110 by the row decoder 121.

The page buffer group 123 includes first to nth page buffers PB1 to PBn.The first to nth page buffers PB1 to PBn are coupled to the memory cellarray 110 respectively through first to nth bit lines BL1 to BLn. Thefirst to nth bit lines BL1 to BLn operate under the control of thecontrol logic 130. Specifically, the first to nth bit lines BL1 to BLnmay operate in response to page buffer control signals PBSIGNALS. Forexample, the first to nth page buffers PB1 to PBn may temporarily storedata received through the first to nth bit lines BL1 to BLn, or sensevoltages or current of the bit lines BL1 to BLn in a read or verifyoperation.

Specifically, in a program operation, the first to nth page buffers PB1to PBn may transfer data DATA received through the input/output circuit125 to selected memory cells through the first to nth bit lines BL1 toBLn, when a program voltage is applied to a selected word line. Memorycells of a selected page are programmed according to the transferreddata DATA. In a program verify operation, the first to nth page buffersPB1 to PBn read page data by sensing voltages or currents received fromthe selected memory cells through the first to nth bit lines BL1 to BLn.

In a read operation, the first to nth page buffers PB1 to PBn read dataDATA from the memory cells of the selected page through the first to nthbit lines BL1 to BLn, and output the read data DATA to the input/outputcircuit 125 under the control of the column decoder 124.

In an erase operation, the first to nth page buffers PB1 to PBn mayfloat the first to nth bit lines BL1 to BLn or apply an erase voltage.

The column decoder 124 may communicate data between the input/outputcircuit 125 and the page buffer group 123 in response to a columnaddress CADD. For example, the column decoder 124 may communicate datawith the first to nth page buffers PB1 to PBn through data lines DL, orcommunicate data with the input/output circuit 125 through column linesCL.

The input/output circuit 125 may transfer a command CMD and an addressADDR, which are received from a memory controller (e.g., the memorycontroller 200 in FIG. 2), to the control logic 130, or exchange dataDATA with the column decoder 124.

In a read operation or verify operation, the sensing circuit 126 maygenerate a reference current in response to an allow bit VRYBIT signal,and output a pass or fail signal PASS/FAIL by comparing a sensingvoltage VPB received from the page buffer group 123 and a referencevoltage generated by the reference current.

The control logic 130 may control the peripheral circuit 120 byoutputting the operation signal OPSIG, the row address RADD, the pagebuffer control signals PBSIGNALS, and the allow bit VRYBIT in responseto the command CMD and the address ADDR. For example, the control logic130 may control a read operation of a selected memory block in responseto a sub-block read command and an address. Also, the control logic 130may control an erase operation a selected sub-block included in theselected memory block in response to a sub-block erase command and anaddress. Also, the control logic 130 may determine whether the verifyoperation has passed or failed in response to the pass or fail signalPASS or FAIL.

Each of the memory cells included in the memory cell array 110 may beprogrammed to a program state among a plurality of program statesaccording to data stored therein. A target program state of a memorycell may be determined as one of the plurality of program statesaccording to data stored in the memory cell.

FIG. 4 is a diagram illustrating a memory block.

Referring to FIGS. 3 and 4, FIG. 4 is a circuit diagram illustrating amemory block BLKa among the plurality of memory blocks BLK1 to BLKzincluded in the memory cell array 110 shown in FIG. 3.

In the memory block BLKa, a first select line, word lines, and a secondselect line, which are arranged in parallel, may be coupled to eachother. For example, the word lines may be arranged in parallel betweenthe first and second select lines. The first select line may be a sourceselect line SSL, and the second select line may be a drain select lineDSL.

More specifically, the memory block BLKa may include a plurality ofstrings coupled between bit lines BL1 to BLn and a source line SL. Thebit lines BL1 to BLn may be respectively coupled to the strings, and thesource line SL may be commonly coupled to the strings. The strings maybe configured identically to one another, and therefore, a string STcoupled to a first bit line BL1 is described in detail as an example.

The string ST may include a source select transistor SST, a plurality ofmemory cells F1 to F16, and a drain select transistor DST, which arecoupled in series to each other between the source line SL and the firstbit line BL1. At least one source select transistor SST and at least onedrain select transistor DST may be included in one string ST, and morethan 16 memory cells (F1 to F16) shown in the drawing may be included inone string ST.

A source of the source select transistor SST may be coupled to thesource line SL, and a drain of the drain select transistor DST may becoupled to the first bit line BL1. The memory cells F1 to F16 may becoupled in series between the source select transistor SST and the drainselect transistor DST. Gates of source select transistors SST includedin different strings may be coupled to the source select line SSL, andgates of drain select transistors DST included in different strings maybe coupled to the drain select line DSL. Gates of the memory cells F1 toF16 may be respectively coupled to a plurality of word lines WL1 toWL16. A group of memory cells coupled to the same word line among memorycells included in different strings may be referred to as a physicalpage PPG. Therefore, physical pages corresponding to the number of theword lines WL1 to WL16 may be included in the memory block BLKa.

One memory cell may store data of one bit. The memory cell is generallyreferred to as a single level cell (SLC). One physical page PPG maystore one logical page (LPG) data. The one LPG data may include a numberof data bits which number correspond to that of cells included in onephysical page PPG. Alternately, one memory cell MC may store data of twoor more bits. The memory cell is generally referred to as a multi-levelcell (MLC). One physical page PPG may store two or more LPG data.

A memory cell for storing data of two or more bits is generally referredto as the MLC. As memory cells with higher storage capacity have beendeveloped, the term MLC has taken on a more specific meaning, referringto a memory cell for storing data of two bits. In that case, a memorycell for storing data of three or more bits is referred to as a triplelevel cell (TLC), and a memory cell for storing data of four or morebits is referred to as a quadruple level cell (QLC). Embodiments of thepresent disclosure may be applied to memory systems with memory cells inwhich data of two or more bits are stored per cell.

In another embodiment, each of the plurality of memory blocks may have athree-dimensional structure. Each memory block may include a pluralityof memory cells stacked on a substrate. The plurality of memory cellsmay be arranged along +X, +Y, and +Z directions.

FIG. 5 is a diagram illustrating an embodiment of a plurality of memorydevices coupled to a memory controller via a plurality of channels,respectively.

Referring to FIG. 5, FIG. 5 illustrates a plurality of memory devices ofthe storage device 50 shown in FIG. 2, coupled to the memory controller200. In FIG. 5, there are four, i.e., first to fourth memory devices100_1 to 100_4, memory devices, although embodiments of the presentdisclosure are not limited to that number. In plural memory deviceembodiments, the storage device 50 may include any suitable number ofmemory devices.

In the illustrated embodiment, the memory controller 200 may be coupledto the first memory device 100_1 through a first channel CH1, be coupledto the second memory device 100_2 through a second channel CH2, becoupled to the third memory device 100_3 through a third channel CH3,and be coupled to the fourth memory device 100_4 through a fourthchannel CH4.

In an embodiment, each of the first to fourth channels CH1 to CH4 mayinclude not only a channel for transmitting data received from the host300 (shown in FIG. 1) but also a channel for applying or interrupting adummy toggle.

The memory controller 200 may generate a command corresponding to arequest received from the host 300 (shown in FIG. 1), and output thegenerated command to one of the first to fourth memory devices 100_1 to100_4. The request received from the host 300 may be a program request,read request or erase request for one of the first to fourth memorydevices 100_1 to 100_4.

For example, when the request received from the host 300 is a readrequest for the first memory device 100_1, the memory controller 200 maygenerate a command corresponding to the read request, and output thegenerated command to the first memory device 100_1 through the firstchannel CH1. The memory controller 200 may also output an addresscorresponding to the read request, in addition to the commandcorresponding to the read request, to the first memory device 100_1through the first channel CH1.

When the request received from the host 300 is a program request for thesecond memory device 100_2, the memory controller 200 may generate acommand corresponding to the program request, and output the generatedcommand to the second memory device 100_2 through the second channelCH2. The memory controller 200 may also output an address and data,which correspond to the program request, to the second memory device100_2 through the second channel CH2.

As described above, the memory controller 200 may generate a command, anaddress, and/or data, which correspond to a request received from thehost 300. When the corresponding request is for the first memory device100_1, the memory controller 200 may output the generated command, thegenerated address, and/or the generated data through the first channelCH1. When the corresponding request is for the second memory device100_2, the memory controller 200 may output the generated command, thegenerated address, and/or the generated data through the second channelCH2. When the corresponding request is for the third memory device100_3, the memory controller 200 may output the generated command, thegenerated address, and/or the generated data through the third channelCH3. When the corresponding request is for the fourth memory device100_4, the memory controller 200 may output the generated command, thegenerated address, and/or the generated data through the fourth channelCH4.

Consequently, the memory controller 200 may communicate with a pluralityof memory devices through a plurality of channels.

In an embodiment, when each of the plurality of memory devices performsan operation corresponding to a command received through a channel,current may be consumed. In particular, when the plurality of memorydevices simultaneously start or end operations, a total currentconsumption of the plurality of memory devices may be rapidly increasedor decreased. When the total current consumption is rapidly increased ordecreased, noise occurs in a voltage source, therefore, the reliabilityof an operation may be deteriorated.

Accordingly, embodiments of the present disclosure provide a method forsequentially applying a dummy pulse to the channels, when the first tofourth memory devices 100_1 to 100_4 simultaneously start operations.Also, embodiments of the present disclosure provide a method forapplying a dummy pulse to the channels and then sequentiallyinterrupting the dummy pulse, when the first to fourth memory devices100_1 to 100_4 simultaneously end operations.

FIG. 6 is a diagram illustrating another embodiment of the memorydevices coupled to the plurality of channels.

Like the arrangement shown in FIG. 5, in FIG. 6 multiple memory devices(first to eighth memory devices 100_1 to 100_8 in this case) may becoupled to the memory controller 200 through multiple channels. However,while FIG. 5 illustrates a structure in which one memory device iscoupled to one channel, FIG. 6 illustrates a structure in which twomemory devices are coupled to one channel. In another embodiment, threeor more memory devices may be coupled to one channel.

In an embodiment, the first memory device 100_1 and the second memorydevice 100_2 are coupled to the first channel CH1 through a first wayWAY1 and a second way WAY2, respectively. In addition, the third memorydevice 100_3 and the fourth memory device 100_4 are coupled to thesecond channel CH2 through a third way WAY3 and a fourth way WAY4,respectively.

In an embodiment, the fifth memory device 100_5 and the sixth memorydevice 100_6 are coupled to the third channel CH3 through a fifth wayWAY 5 and a sixth way WAY6, respectively. In addition, the seventhmemory device 100_7 and the eighth memory device 100_8 are coupled tothe fourth channel CH4 through a seventh way WAY 7 and an eighth wayWAY8, respectively.

In an embodiment, each of the first to fourth channels CH1 to CH4 mayinclude not only a channel for transmitting data received from the host300 but also a channel for applying or interrupting a dummy toggle.

In an embodiment, the memory controller 200 may generate a commandcorresponding to a request received from the host 300, and output thegenerated command to any one of the first to eighth memory devices 100_1to 100_8. The request received from the host 300 may be a programrequest, read request or erase request for any one of the first toeighth memory devices 100_1 to 100_8.

For example, when the request received from the host 300 is a readrequest for the first memory device 100_1, the memory controller 200 maygenerate a command corresponding to the read request, and output thegenerated command to the first memory device 100_1 through the firstchannel CH1. The memory controller 200 may also output an addresscorresponding to the read request, in addition to the commandcorresponding to the read request, to the first memory device 100_1through the first channel CH1.

When the request received from the host 300 is a program request for thesecond memory device 100_2, the memory controller 200 may generate acommand corresponding to the program request, and output the generatedcommand to the second memory device 100_2 through the first channel CH1.The memory controller 200 may also output an address and data, whichcorrespond to the program request, to the second memory device 100_2through the first channel CH1.

As described above, when the request received from the host 300 is arequest for the first memory device 100_1 or the second memory device100_2, the memory controller 200 may output a command, an address,and/or data, which correspond to the request from the host 300, to thefirst memory device 100_1 or the second memory device 100_2 through thefirst channel CH1. In addition, when the request received from the host300 is a request for the third memory device 100_3 or the fourth memorydevice 100_4, the memory controller 200 may output a command, anaddress, and/or data, which correspond to the request from the host 300,to the third memory device 100_3 or the fourth memory device 100_4through the second channel CH2.

In an embodiment, when the request received from the host 300 is arequest for the fifth memory device 100_5 or the sixth memory device100_6, the memory controller 200 may output a command, an address,and/or data, which correspond to the request from the host 300, to thefifth memory device 100_5 or the sixth memory device 100_6 through thethird channel CH3. In addition, when the request received from the host300 is a request for the seventh memory device 100_7 or the eighthmemory device 100_8, the memory controller 200 may output a command, anaddress, and/or data, which correspond to the request from the host 300,to the seventh memory device 100_7 or the eighth memory device 100_8through the fourth channel CH4.

Consequently, as in the arrangement shown in FIG. 5, in the arrangementof FIG. 6, the memory controller 200 may communicate with a plurality ofmemory devices through a plurality of channels.

In an embodiment, when each of the plurality of memory devices performsan operation corresponding to a command received through a channel,current may be consumed. In particular, when the plurality of memorydevices simultaneously start or end operations, a total currentconsumption of the plurality of memory devices may rapidly increase ordecrease. When the total current consumption rapidly increases ordecreases, noise occurs in a voltage source, therefore, the reliabilityof an operation may deteriorate.

According to embodiments of the present disclosure, in order to preventrapid change of the total current consumption, the memory controller 200may apply a dummy pulse to the channels before the plurality of memorydevices start operations, or apply a dummy pulse to the channels whenthe memory devices end operations and then sequentially interrupt thedummy pulse, or both.

FIG. 7 is a diagram illustrating a change in total current consumptionand noise of a voltage source, when memory devices coupled to aplurality of channels simultaneously start or end operations.

Referring to FIG. 7, the horizontal axis represents time t, and thevertical axis represents a total current consumption I_TOT of theplurality of memory devices and a voltage source Vsource applied to theplurality of memory devices. The voltage source Vsource applied to theplurality of memory devices is V1 in the present example.

In an embodiment, each of the plurality of memory devices coupled to thememory controller through the plurality of channels may perform anoperation corresponding to a command received from the memorycontroller. The plurality of memory devices may perform operationssimultaneously or at different times.

FIG. 7 illustrates a total current consumption I_TOT and a voltagesource Vsource when the plurality of memory devices simultaneouslyperform operations.

Referring to FIG. 7, a voltage applied to the plurality of memorydevices may be constantly maintained. However, when the plurality ofmemory devices simultaneously start or end operations, noise may occurin the voltage source.

For example, at t1, the plurality of memory devices may simultaneouslystart operations. Therefore, at t1, a total current consumption I_TOT ofthe plurality of memory devices may rapidly increase from Ia to I1.Noise occurs in the voltage source Vsource, and hence the voltage sourcemay be decreased and then again become V1. The presence of noise in thevoltage source Vsource may cause the plurality of memory devices toperform abnormally.

Subsequently, at t2, the plurality of memory devices may simultaneouslyend operations. Therefore, at t2, a total current consumption I_TOT ofthe plurality of memory devices may rapidly decrease from I1 to Ia.Noise occurs in the voltage source Vsource, and hence the voltage sourceVsource may be increased and again become V1. Furthermore, the presenceof noise in the voltage source Vsource may cause the plurality of memorydevices to perform abnormally.

Consequently, when the plurality of memory devices simultaneouslyperform operations, the total current consumption I_TOT may rapidlychange, and noise may occur in the voltage source Vsource. The noise inthe voltage source Vsource may, in turn, cause the plurality of memorydevices to perform abnormally; hence, it is necessary to prevent thetotal current consumption I_TOT from being rapidly changed.

Therefore, in order to prevent noise from occurring in the voltagesource Vsource, operations to be performed on the plurality of memorydevices may be delayed and performed later than they otherwise would beperformed, or operations may be simultaneously performed after a dummypulse is applied to memory devices on which the operations are to beperformed among the plurality of memory devices.

When operations on which the plurality of memory devices are to beperformed are delayed and performed later, the memory devices may becontrolled to perform their operations serially. That is, after onememory device completes an operation, another memory device starts anoperation, until all of the memory devices have completed theirrespective operations. However, according to this serial method, overallprogram time may be lengthened. As a result, program performance may bedecreased. That is, latency corresponding to the delayed time may occur.

Accordingly, embodiments of the present disclosure provide a method forapplying a dummy pulse to, or interrupting a dummy pulse in, channelscoupled to the memory controller and the plurality of memory devices toprevent the total current consumption I_TOT from being rapidly changed.

In accordance with embodiments of the present disclosure, the memorydevices do not delay and perform operations, but simultaneously performthe operations after a dummy pulse is applied to those memory devices,so that fast transmission of data or fast transfer of signals ispossible.

FIG. 8 is a diagram illustrating a change in total current consumptionand noise of a voltage source, when a plurality of memory devicessimultaneously end operations while performing the operations.

Referring to FIG. 8, the horizontal axis represents time t, and thevertical axis represents a total current consumption I_TOT of theplurality of memory devices and a voltage source Vsource applied to theplurality of memory devices. The voltage source Vsource applied to theplurality of memory devices is V3 in this example.

Referring to FIGS. 7 and 8, while FIG. 7 illustrates a total currentconsumption I_TOT and a voltage source Vsource when the plurality ofmemory devices simultaneously start or end operations, FIG. 8illustrates a total current consumption I_TOT and a voltage sourceVsource when the plurality of memory devices simultaneously suspend orend operations then start the operations again. Here, the plurality ofmemory device initially start the operations at different times.

In FIG. 8, a case where the memory controller is coupled to a firstmemory device through a first channel and is coupled to a second memorydevice through a second channel is shown.

In an embodiment, at t3, the first memory device may start an operation.Therefore, the total current consumption I_TOT may increase from Ia toI2. That is, the total current consumption I_TOT when the first memorydevice performs the operation may be I2. Since the total currentconsumption I_TOT does not rapidly increase, the voltage source Vsourcemay be maintained as V3.

Subsequently, at t4, the second memory device may start an operation.Therefore, the total current consumption I_TOT may increase from I2 toI3. When the first memory device starts the operation at t3, the totalcurrent consumption I_TOT increases to I2. However, because theadditional increase of the total current consumption I_TOT to I3 at t4when the second memory device starts an operation is not a rapidincrease, the voltage source Vsource may be maintained as V3.

At t4 to t5, both the first and second memory devices are performing theoperations. Therefore, the total current consumption I_TOT may be I3,and the voltage source Vsource may be V3.

Subsequently, at t5, both the first and second memory devices may endthe operations. That is, the first and second memory devices may have anidle period or interval (t5 to t6) in which the first and second memorydevices temporarily end (or suspend) the operations. Since the first andsecond memory devices simultaneously end the operations, the totalcurrent consumption I_TOT may rapidly decrease, and then rapidlyincrease again when the first and second memory devices simultaneouslystart (or resume) the operations.

Therefore, during the interval t5 to t6, noise may occur in the voltagesource Vsource. That is, from t5 to t6, the voltage source Vsource maybe increased, when the total current consumption I_TOT rapidlydecreases. When the total current consumption I_TOT rapidly increases,the voltage source Vsource may decrease, then become V3 again.

Consequently, from t5 to t6, noise may occur in the voltage source, whenthe total current consumption I_TOT changes.

In an embodiment, both the first and second memory devices may end theoperations and then start the operations again at t6, and continueperforming the operations after t6 until t7. That is, the first andsecond memory devices may have another idle period from t7 to t8. As inthe interval t5 to t6, in the interval t7 to t8, noise may occur in thevoltage source Vsource, as a result of a rapid decrease followed by arapid increase in the total current consumption I_TOT.

Subsequently, at t9, the first memory device may end the operation.Therefore, the total current consumption I_TOT may decrease from I3 toI4. That is, the total current consumption I_TOT when the second memorydevice alone performs the operation may be I4. Since the total currentconsumption I_TOT does not rapidly decrease, the voltage source Vsourcemay be maintained as V3.

At t10, the second memory device may also end the operation. Therefore,the total current consumption I_TOT may decrease from I4 to Ia. Similarto t9, since the total current consumption I_TOT does not rapidlydecrease, the voltage source Vsource may be maintained as V3.

Consequently, when the total current consumption I_TOT is rapidlydecreased or increased, noise may occur in the voltage source Vsource,which, in turn, may result in errors in the operations performed by thememory device(s) during that time. Therefore, it is necessary to ensurethat the operations by the plurality of memory devices are performedreliably.

Accordingly, embodiments of the present disclosure provide a method forapplying a dummy pulse through channels, or interrupting a dummy pulseso applied, to prevent noise from occurring in the voltage sourceVsource. Below, an operation of preventing or minimizing the occurrenceof noise in the voltage source Vsource is described.

FIG. 9 is a diagram illustrating a structure of the memory controller200 shown in FIG. 2, which applies a dummy pulse for each channel,according to an embodiment.

Referring to FIG. 9, the memory controller 200 shown in FIG. 9 mayinclude the request checker 210, the dummy manager 220, and the dummypulse generator 230. The memory controller 200 may also include theenable signal generator 240 and the command queue group 250 (both shownin FIG. 2), but for clarity, they are omitted in FIG. 9.

In FIG. 9, by way of example, an arrangement in which the memory device100 in the storage device 50 (shown in FIG. 2) is provided with first tofourth memory devices 100_1 to 100_4 is illustrated. The first to fourthmemory devices 100_1 to 100_4 may be coupled to the memory controller200 respectively through first to fourth channels CH1 to CH4.

Therefore, according to an embodiment of the present disclosure, a dummypulse may be applied to the first to fourth memory devices 100_1 to100_4 through the first to fourth channels CH1 to CH4. The dummy pulsemay be input to the first to fourth channels CH1 to CH4 through anInput/Output pin (IO) pin) of the memory device or through aGeneral-Purpose Input/Output pin (GPIO pin).

In an embodiment, each of the first to fourth channels CH1 to CH4 mayinclude not only a channel for transmitting data received from the host300 but also a channel for applying or interrupting a dummy toggle.

In another embodiment, the storage device 50 may include a smaller orlarger number of memory devices than that shown in FIG. 9.

Although not shown in the drawing, the dummy pulse may be generatedthrough internal elements respectively included in the first to fourthmemory devices 100_1 to 100_4, instead of the memory controller 200.That is, a total current consumption of the memory device may besequentially increased or decreased through such internal elements.

In FIG. 9, an example in which the dummy pulse generator 230 in thememory controller 200 generates the dummy pulse is illustrated.

In an embodiment, the request checker 210 may receive a request(REQUEST) from the host 300. The request received from the host 300 maybe a program request, read request or erase request. The requestreceived from the host 300 may be a request for any one of the first tofourth memory devices 100_1 to 100_4.

The request checker 210 may check which memory device among the first tofourth memory devices 100_1 to 100_4 the received request is for. Thatis, the request checker 210 may identify which memory device(s) amongthe first to fourth memory devices 100_1 to 100_4, has started anoperation based on the request received from the host 300. Subsequently,the request checker 210 may generate device information DEVICE_INFincluding information identifying the memory device(s) in which anoperation is started, and provide the generated device information tothe dummy manager 220.

In an embodiment, the request checker 210 may provide the dummy manager220 with a warm-up enable signal together with or instead of the deviceinformation DEVICE_INF. The warm-up enable signal may represent which,and how many, channels are coupled to memory devices in which operationsare started among the first to fourth memory devices 100_1 to 100_4.That is, the warm-up enable signal may represent a number of memorydevices on which operations are performed, channels coupled to thecorresponding memory devices, and numbers of the channels.

In an embodiment, the request checker 210 may identify the memorydevices in which operations are started, based on the request receivedfrom the host 300, and then output the warm-up enable signal.

Therefore, in order to provide the dummy manager 220 with information onthe memory devices in which operations are started, the request checker210 may output the warm-up enable signal together with or instead of thedevice information DEVICE_INF.

In an embodiment, the dummy manager 220 may output a dummy pulsegeneration request DPGE_REG to the dummy pulse generator 230, based onthe device information DEVICE_INF and/or the warm-up enable signal,received from the request checker 210. That is, the dummy manager 220may control a current to be applied to channels coupled to memorydevices in which operations are started. The device informationDEVICE_INF and the warm-up enable signal may indicate two or more memorydevices in which operations are started.

Specifically, when the device information DEVICE_INF and/or the warm-upenable signal represent that only one memory device performs anoperation, the dummy manager 220 may not operate to apply currentcontrol. However, when the device information DEVICE_INF and/or thewarm-up enable signal represent that two or more memory devices performoperations, the dummy manager 220 may control a current to be applied tochannels before the memory devices coupled to those channels start theoperations.

In an example, information representing that the first and second memorydevices 100_1 and 100_2, coupled to channels CH1 and CH2 respectively,are to start operations may be included in the device informationDEVICE_INF or the warm-up enable signal and may be output. The dummymanager 220 may output the dummy pulse generation request DPGE_REQ forrequesting the dummy pulse to be sequentially applied to the first andsecond channels CH1 and CH2 based on the device information DEVICE_INFor the warm-up enable signal.

The dummy pulse generator 230 may generate the dummy pulse before thefirst and second memory devices 100_1 and 100_2 start the operations,based on the dummy pulse generation request DPGE_REQ, and apply thedummy pulse to the first channel CH1 coupled to the first memory device100_1 or the second channel CH2 coupled to the second memory device100_2. That is, the dummy pulse generator 230 may first apply the dummypulse to one of the two channels respectively coupled to two memorydevices in which operations are started. Subsequently, after a set timeelapses from the first application of the dummy pulse to one channel,the dummy pulse generator 230 may apply the dummy pulse to the otherchannel associated with the other memory device.

In another example, information representing that the first to fourthmemory devices 100_1 to 100_4 are coupled to four channels CH1 to CH4respectively, are to start operations may be included in the deviceinformation DEVICE_INF or the warm-up enable signal and may be output.The dummy manager 220 may output the dummy pulse generation requestDPGE_REQ for requesting the dummy pulse to be sequentially applied tothe first to fourth channels CH1 to CH4 based on the device informationDEVICE_INF or the warm-up enable signal.

The dummy pulse generator 230 may generate the dummy pulse before thefirst to fourth memory devices 100_1 to 100_4 start the operations,based on the dummy pulse generation request DPGE_REQ, and apply thedummy pulse to the first channel CH1, the second channel CH2, the thirdchannel CH3, or the fourth channel CH4. That is, the dummy pulsegenerator 230 may apply the dummy pulse to one of four channels coupledto a memory device in which an operation is started. Subsequently, aftera set time elapses from a previous application of the dummy pulse, thedummy pulse generator 230 may apply the dummy pulse to a channel coupledto one of the remaining memory devices. Thus, the dummy pulse may besequentially applied to the channels associated with memory devices inwhich operations are performed.

Sequentially applying the dummy pulse as described above, preventsinstantaneous change in total current consumption of memory devices, andprevents occurrence of noise in the system.

In another embodiment, the memory controller 200 does not receive therequest REQUEST from the host 300. Instead, the memory controller 200may autonomously generate the dummy pulse and apply the dummy pulse tothe first to fourth channels CH1 to CH4. That is, before the first tofourth memory devices 100_1 to 100_4 start operations, the memorycontroller 200 may autonomously generate the dummy pulse and apply thedummy pulse to each channel.

For example, when an operation of any one of the first to fourth memorydevices 100_1 to 100_4 is required based on an internal operation of thememory device 200, such as Garbage Collection (GC), the memorycontroller 200 may autonomously generate the dummy pulse and apply thedummy pulse to a channel. Therefore, the memory controller 200 mayautonomously generate the dummy pulse, even in the absence of therequest REQUEST received from the host 300.

FIG. 10 is a diagram illustrating a method for sequentially increasingand decreasing a total current consumption.

Referring to FIGS. 9 and 10, FIG. 10 illustrates channel currents I_CH1to I_CH4 and a total current consumption I_TOT according to an operationof the dummy pulse generator 230 shown in FIG. 9 after informationrepresenting that the first to fourth memory devices 100_1 to 100_4 areto start operation is included in the device information DEVICE_INF orthe warm-up enable signal, and the dummy manager 220 outputs the dummypulse generation request DPGE_REQ for requesting the dummy pulse to besequentially applied to the first to fourth channels CH1 to CH4respectively coupled to the first to fourth memory devices 100_1 to100_4, based on the device information DEVICE_INF or the warm-up enablesignal.

In an embodiment, when it is determined that the first to fourth memorydevices are to start the operations, at t11, the dummy pulse may beapplied to one channel coupled to one memory device, which channel maybe the first, second, third or fourth. Here, by way of example, thedummy pulse is first applied to the first channel.

At t11, when the dummy pulse is applied to the first channel, a firstchannel current I_CH1 may increase to a dummy current I_DUMMY.Therefore, the total current consumption I_TOT may also increase.

Subsequently, at t12, the dummy pulse may be applied to one of theremaining channels coupled to the second memory device. t12 may occur aset time after t11. Here, by way of example, that channel is the secondchannel.

At t12, when the dummy pulse is applied to the second channel, a secondchannel current I_CH2 may increase to the dummy current I_DUMMY.Therefore, the total current consumption I_TOT may also increase.

Subsequently, the dummy pulse may be sequentially applied to the otherremaining channels. For example, at t13, the dummy pulse may be appliedto the third channel, so that a third channel current I_CH3 becomes thedummy current I_DUMMY. At t14, which may occur a set amount of timeafter t13, the dummy pulse may be applied to the fourth channel, so thata fourth channel current I_CH4 becomes the dummy current I_DUMMY.

That is, the dummy manager 220 shown in FIG. 9 may sequentially increasethe total current consumption I_TOT by determining a set time and achannel to which the dummy pulse is to be applied. In addition, thetotal current consumption I_TOT may be sequentially increased byadjusting a level of the dummy pulse or a duration of the dummy pulse.

A method for sequentially increasing the total current consumption I_TOTby adjusting the level of the dummy pulse according to anotherembodiment will be described below with reference to FIG. 11.

Therefore, the total current consumption I_TOT may be sequentiallyincreased from t11 to t14. When the sequentially increased currentreaches a certain level, memory devices determined to perform operationsmay perform the respective operations. That is, after t15, the memorydevices may perform the respective operations. Here, right after therespective operations are performed, the dummy manager 220 may determineinterrupting the applying a dummy pulse. Namely, since the memorydevices start to operate, the dummy pulse no longer needs to begenerated for increasing the total current consumption progressively.

Consequently, when the total current consumption I_TOT is sequentiallyincreased, noise may not occur in the voltage source Vsource. Thus, thedummy pulse generator 230 sequentially applies the dummy pulse tochannels, so that the reliability of operations performed by memorydevices can be ensured.

It may be determined that the first to fourth memory devices all end theoperations after the first to fourth memory devices perform theoperations.

When the first to fourth memory devices simultaneously end theoperations, the total current consumption I_TOT of the memory devicesmay be rapidly decreased. Therefore, the dummy pulse may be applied tothe first to fourth channels respectively coupled to the first to fourthmemory devices. Subsequently, the dummy pulses applied to the respectivechannels may be sequentially interrupted. That is, after applying thedummy pulse is interrupted, the dummy pulses are applied to respectivechannels coupled to the first to fourth memory devices.

For example, at t16, when it is determined that the first to fourthmemory devices do not perform the operations, the dummy pulse may beapplied to the first to fourth channels. That is, at t16, the first tofourth channel currents I_CH1 to I_CH4 may become the dummy currentI_DUMMY.

Subsequently, at t17, which may occur a set amount of time after t16,the dummy pulse generator 230 may interrupt the dummy pulse applied toone of the channels, which may be the first, second, third or fourthchannel. Here, by way of example, the dummy pulse in the first channelis interrupted at t17.

At t17, when the application of the dummy pulse to the first channel isended, the first channel current I_CH1 may be decreased. Therefore, thetotal current consumption I_TOT may also be decreased.

Subsequently, at t18, the dummy pulse applied to the second channelcoupled to the second memory device may be interrupted. t18 may occur aset amount of time after t17. More generally, at t18, the channel inwhich the dummy pulse is interrupted may be any of the channels in whichthe dummy pulse has not yet been interrupted.

At t18, when the dummy pulse is interrupted from the second channel, thesecond channel current I_CH2 may be decreased. Therefore, the totalcurrent consumption I_TOT may also be decreased.

Subsequently, the dummy pulse may be sequentially interrupted in theother channels. For example, at t19, which may occur a set amount oftime after t18, the dummy pulse applied to the third channel may beinterrupted. At t20, which may occur a set amount of time after t19, thedummy pulse applied to the fourth channel may be interrupted.

Therefore, the total current consumption I_TOT may be sequentiallydecreased from t17 to t20. Consequently, when the total currentconsumption I_TOT is sequentially decreased, noise may not occur in thevoltage source Vsource. Thus, the dummy pulses applied to the channelsare sequentially interrupted, so that the reliability of the operationsperformed by the memory devices can be ensured.

FIG. 11 is a diagram illustrating another embodiment of sequentiallyincreasing and decreasing a total current consumption.

Referring to FIGS. 9, 10, and 11, FIG. 11 illustrates an embodiment inwhich more subdivided dummy pulses are applied from t11 to t14 shown inFIG. 10. FIG. 11 illustrates channel currents I_CH1 to I_CH4 and a totalcurrent consumption I_TOT according to an operation of the dummy pulsegenerator 230 after information representing that the first to fourthmemory devices 100_1 to 100_4 shown in FIG. 9 are to start operation isincluded in the device information, and the dummy manager 220 outputsthe dummy pulse generation request for requesting the dummy pulse to besequentially applied to the first to fourth channels CH1 to CH4respectively coupled to the first to fourth memory devices 100_1 to100_4, based on the device information.

In describing FIG. 11, content already described in connection with FIG.10 is omitted.

In an embodiment, the dummy manager 220 may determine that the dummypulse is to be applied first to the first channel coupled to the firstmemory device among the first to fourth memory devices. The dummy pulsegenerator 230 may generate the dummy pulse step by step. The dummy pulsegenerator 230 may generate the dummy pulse by adjusting a level of thedummy pulse. Therefore, the dummy pulse generator 230 may generate thedummy pulse such that the total current consumption I_TOT is increasedstep by step.

For example, at t11 a, the dummy pulse generator 230 may generate adummy pulse and apply the dummy pulse to the first channel, and thefirst channel current I_CH1 may become a step current I_STEP.Subsequently, at t11, the dummy pulse generator 230 may generate a dummypulse having a level higher than that of the previous dummy pulse andapply the dummy pulse to the first channel, and the first channelcurrent I_CH1 may become the dummy current I_DUMMY.

Like the arrangement in FIG. 10, in the arrangement of FIG. 11, thedummy pulse generator 230 applies the dummy pulse through the firstchannel, and the first channel current I_CH1 becomes the dummy currentI_DUMMY. However, in the arrangement of FIG. 11, the dummy pulsegenerator 230 applies pulses having different levels to the firstchannel, so that a change in the total current consumption I_TOT can beminimized.

The dummy pulse may also be applied step by step to the second to fourthchannels.

For example, after a reference time elapses, at t12 a, the secondchannel current I_CH2 may become the step current I_STEP by applying adummy pulse to the second channel. At t12, the second channel currentI_CH2 may become the dummy current I_DUMMY by applying, to the secondchannel, a dummy pulse having a level higher than that of the previousdummy pulse.

In addition, after the reference time elapses, at t13 a, the thirdchannel current I_CH3 may become the step current I_STEP by applying adummy pulse to the third channel. At t13, the third channel currentI_CH3 may become the dummy current I_DUMMY by applying, to the thirdchannel, a dummy pulse having a level higher than that of the previousdummy pulse.

Finally, at t14 a, the fourth channel current I_CH4 may become the stepcurrent I_STEP by applying a dummy pulse to the fourth channel. At t14,the fourth channel current I_CH4 may become the dummy current I_DUMMY byapplying, to the fourth channel, a dummy pulse having a level higherthan that of the previous dummy pulse.

Consequently, the dummy pulse applied to the first to fourth channels issubdivided, so that the total current consumption can be more graduallyincreased. Thus, it is less likely that noise will occur in the voltagesource, so that the reliability of an operation performed by the memorydevice can be increased.

The above-described method may be also be applied when the dummy pulsesapplied to the respective channels are sequentially interrupted. Thatis, the dummy pulse interrupted for each channel is subdivided, so thatthe total current consumption can be more gradually decreased. Thus, itis less likely that noise will occur in the voltage source, so that thereliability of an operation performed by the memory device can beensured.

FIG. 12 is a diagram illustrating a structure of the memory controller200 shown in FIG. 2, which sequentially decreases a total currentconsumption, according to an embodiment.

Referring to FIG. 12, the memory controller 200 may include the dummymanager 220, the dummy pulse generator 230, the enable signal generator240, and the command queue group 250. The memory controller 200 may alsoinclude the request checker 210 shown in FIG. 1 but such component isomitted here for clarity.

FIG. 12 illustrates a method for interrupting a dummy pulse when it isdetermined that at least one memory device among the first to fourthmemory devices 100_1 to 100_4 has ended or suspended performance of anoperation.

In an embodiment, each of first to fourth channels CH1 to CH4 mayinclude not only a channel for transmitting data received from the host300 but also a channel for applying or interrupting a dummy toggle.

In an embodiment, the enable signal generator 240 may generate a chipenable signal CE_SIG corresponding to a physical block address PBA, andoutput the generated chip enable signal CE_SIG to a selected memorydevice and the dummy manager 220. The chip enable signal CE_SIG may befor selecting a memory device on which an operation is performed orreleasing the selection. The chip enable signal CE_SIG may be in a highstate or low state. When the chip enable signal CE_SIG is in the highstate, the selection of the memory device may be released. When the chipenable signal CE_SIG in the low state, the memory device may beselected. In other words, a high-state chip enable signal CE_SIG may beinput to the memory device in a standby state, and a low-state chipenable signal CE_SIG may be input to the memory device that isoperating.

For example, when the first memory device 100_1 is to end an operation,the enable signal generator 240 may generate a chip enable signal CE_SIGin the high state, which releases the selection of the first memorydevice 100_1. The enable signal generator 240 may provide the generatedchip enable signal CE_SIG to the dummy manager 220.

The dummy manager 220 may determine whether a chip enable signal CE_SIGin the high state, which corresponds to at least two memory devices, hasbeen received in response to the chip enable signal CE_SIG received fromthe enable signal generator 240.

When the dummy manager 220 receives a chip enable signal CE_SIG in thehigh state, which corresponds to two or more memory devices, the dummymanager 220 may output, to the command queue group 250, a command queuelevel request CMDQL_REQ for checking a command queue level CMDQL of acorresponding memory device. The command queue level CMDQL may beindicative of a number of commands queued in a command queue. That is,when the number of the queued command is “0,” the command queue levelCMDQL may be “0.” When the number of the queued command is “5,” thecommand queue level CMDQL may be “5.”

The command queue group 250 may output a command queue level CMDQLcorresponding to the corresponding memory device, to the dummy manager220 in response to the command queue level request CMDQL_REQ receivedfrom the dummy manager 220.

In an embodiment, the dummy manager 220 may determine a channel to whichthe dummy pulse is to be applied, based on the chip enable signal CE_SIGin the high state and the command queue level CMDQL.

For example, when command queue levels CMDQL of all the memory devicesare “0,” the dummy manager 220 may determine to apply the dummy pulse toall the memory devices and then sequentially interrupt the dummy pulse.In an embodiment, the dummy manager 220 may output a dummy pulse inputrequest DPIN_REQ to the dummy pulse generator 230. In response to theinput request DPIN_REQ, the dummy pulse generator 230 may sequentiallyinterrupt applying the dummy pulse.

However, when command queue levels CMDQL of some but not all memorydevices are “0,” the dummy manager 220 may apply the dummy pulse to onlychannels coupled to the memory devices of which command queue levelsCMDQL are not “0.” That is, the dummy pulse is applied to memory devicespredicted to again perform operations within a short time, so that atotal current consumption is prevented from being rapidly increased ordecreased. The number of memory devices of which command queue levelsCMDQL are not “0” may be 1.

After the dummy pulse is applied to only remaining memory devices ofwhich command queue levels CMDQL are not “0,” the dummy manager 220 mayagain receive the chip enable signal CE_SIG in the high state from theenable signal generator 240. When the dummy manager 220 receives a chipenable signal CE_SIG in the high state, which corresponds to at leasttwo memory devices, the dummy manager 220 may receive command queuelevels CMDQL corresponding to memory devices of the high-state chipenable signal CE_SIG and then determine whether the dummy pulse is to beapplied or interrupted.

FIG. 13 is a diagram illustrating application or interruption of a dummypulse, which is determined based on a command queue, according to anembodiment.

Referring to FIGS. 12 and 13, first to fourth command queues CMD_QUEUE1to CMD_QUEUE4 shown in FIG. 13 respectively correspond to the first tofourth memory devices (e.g., the first to fourth memory devices 100_1 to100_4 shown in FIG. 12), and each column shown in FIG. 13 represents asequence of commands to be executed by a corresponding memory device.

In an embodiment, first to fifth commands CMD1 to CMD5 may be queued inthe first command queue CMD_QUEUE1 corresponding to the first memorydevice, sixth and seventh commands CMD6 and CMD7 may be queued in thesecond command queue CMD_QUEUE2 corresponding to the second memorydevice, eighth to eleventh commands CMD8 to CMD11 may be queued in thethird command queue CMD_QUEUE3 corresponding to the third memory device,and twelfth to fourteenth commands CMD12 to CMD14 may be queued in thefourth command queue CMD_QUEUE4 corresponding to the fourth memorydevice.

FIG. 13 shows specific numbers and sequences of commands queued in therespective queues. The numbers and sequences, however, may vary.

In an embodiment, the first to fourth memory devices may simultaneouslyperform operations. That is, the first memory device, the second memorydevice, the third memory device, and the fourth memory device maysimultaneously perform operations respectively corresponding to thefirst command CMD1, the sixth command CMD6, the eighth command CMD8, andthe twelfth command CMD12.

Referring to FIG. 10, before the first to fourth memory devices performoperations corresponding to the respective commands, a dummy pulse maybe sequentially applied to the first to fourth channels respectivelycoupled to the first to fourth memory devices. When the dummy pulse issequentially applied to the first to fourth channels, a total currentconsumption of the memory devices may be sequentially increased.Therefore, when the total current consumption is sequentially increased,voltage noise may not occur.

When the first to fourth channel currents become the dummy current asthe dummy pulse is applied to the first to fourth channels, the first tofourth memory devices may perform the operations corresponding to therespective commands.

In an embodiment, the first to fourth memory devices may execute nextcommands. That is, the first memory device may perform an operationcorresponding to the second command CMD2, the second memory device mayperform an operation corresponding to the seventh command CMD7, thethird memory device may perform an operation corresponding to the ninthcommand CMD9, and the fourth memory device may perform an operationcorresponding to the thirteenth command CMD13.

Since no memory device among the first to fourth memory devices hasended or suspended operation, the enable signal generator 240 maygenerate a chip enable signal in a low state, which corresponds to thefirst to fourth memory devices. Therefore, it is unnecessary for thedummy manager 220 to perform an operation for sequentially decreasingthe total current consumption of the memory devices.

However, when it is determined that, for example, the second and thirdmemory devices end their operations after the first to fourth memorydevices perform the respective operations, the enable signal generator240 may generate a chip enable signal in a high state, which correspondsto the second and third memory devices. After the second memory deviceperforms the operation corresponding to the seventh command CMD7, thesecond memory device may end the operation. After the third memorydevice performs the operation corresponding to the ninth command CMD9,the third memory device may end the operation.

Since no current is consumed in the two memory devices, the totalcurrent consumption may be rapidly decreased. Therefore, the dummymanager 220 may receive the chip enable signal in the high state, whichcorresponds to the second and third memory devices, and then output, tothe command queue group 250, a command queue level request for checkingcommand queue levels of the second and third memory devices.

In an embodiment, the command queue group 250 may output a command queuelevel in response to the command queue level request from the dummymanager 220. Since the second memory device performed the operationscorresponding to the sixth and seventh commands CMD6 and CMD7, a numberof commands queued in a command queue corresponding to the second memorydevice may be “0.” In addition, since the third memory device performedthe operations corresponding to the eighth and ninth commands CMD8 andCMD9, commands queued in a command queue corresponding to the thirdmemory device may be the tenth and eleventh commands CMD10 and CMD11,and a number of the commands may be “2.”

Consequently, in response to the command queue level request from thedummy manager 220, the command queue group 250 may output, to the dummymanager 220, the command queue level “0” corresponding to the secondmemory device and the command queue level “2” corresponding to the thirdmemory device.

Since the command queue level corresponding to the third memory deviceis not “0,” the dummy manager 220 may determine that the dummy pulse isapplied to only the third memory device of which the command queue levelis not “0.” The dummy manager 220 may output, to the dummy pulsegenerator 230, a dummy pulse generation request for requestingapplication of the dummy pulse to the third memory device, and the dummypulse generator 230 may apply the dummy pulse to the third channelcoupled to the third memory device.

In an embodiment, although not shown in the drawing, when both thecommand queue levels corresponding to the second and third memorydevices are “0,” the dummy pulse may be applied to the channelsrespectively coupled to the second and third memory devices. When a settime elapses after the dummy pulse is applied to the second and thirdchannels, the dummy pulses applied to the second and third channels maybe sequentially interrupted.

Subsequently, it may be determined that the first and fourth memorydevices end operations. That is, a chip enable signal in the high statecorresponding to the first and fourth memory devices may be generated.After the first memory device performs an operation corresponding to thethird command CMD3, the first memory device may end the operation. Afterthe fourth memory device performs an operation corresponding to thefourteenth command CMD14, and the fourth memory device may end theoperation.

Since no current is consumed in the two memory devices, the totalcurrent consumption may be rapidly decreased. Therefore, the dummymanager 220 may receive the chip enable signal in the high state, whichcorresponds to the first and fourth memory devices, and then output, tothe command queue group 250, a command queue level request for checkingcommand queue levels of the first and fourth memory devices.

In an embodiment, the command queue group 250 may output a command queuelevel in response to the command queue level request from the dummymanager 220. Since the first memory device performed the operationscorresponding to the first, second, and third commands CMD1, CMD2, andCMD3, commands queued in a command queue corresponding to the firstmemory device may be the fourth and fifth commands CMD4 and CMD5, and anumber of the commands may be “2.” In addition, since the fourth memorydevice performed the operations corresponding to the twelfth tofourteenth commands CMD12 to CMD14, a number of commands queued in acommand queue corresponding to the fourth memory device may be “0.”

Consequently, in response to the command queue level request from thedummy manager, the command queue group 250 may output, to the dummymanager 220, the command queue level “2” corresponding to the firstmemory device and the command queue level “0” corresponding to thefourth memory device.

Since the command queue level corresponding to the first memory deviceis not “0,” the dummy manager 220 may determine that the dummy pulse isapplied to only the first memory device of which the command queue levelis not “0.” The dummy manager 220 may output, to the dummy pulsegenerator 230, a dummy pulse generation request for requestingapplication of the dummy pulse to the first memory device, and the dummypulse generator 230 may apply the dummy pulse to the first channelcoupled to the first memory device.

Subsequently, the first memory device may perform an operationcorresponding to the fourth command CMD4, and the third memory devicemay perform an operation corresponding to the eleventh command CMD11.

In an embodiment, it may be determined that, after the third memorydevice performs the operation corresponding to the eleventh commandCMD11, the third memory device ends the operation. That is, a chipenable signal in the high state corresponding to the third memory devicemay be generated. The third memory device may end the operation afterthe third memory device performs the operation corresponding to theeleventh command CMD11. However, since only the third memory deviceamong the plurality of memory devices ends the operation, it isunnecessary for the dummy manager 220 to perform an operation forapplying or interrupting the dummy pulse.

Consequently, when the memory devices start operations, the totalcurrent consumption of the memory devices may be sequentially increased.Then, when the memory devices end operations, the total currentconsumption of the memory devices may be sequentially decreased. Thus,through the above-described process, a case in which the total currentconsumption is rapidly increased or decreased is prevented, so thatoccurrence of power noise can be prevented.

FIG. 14 is a diagram illustrating a dummy pulse output based on a chipenable signal according to an embodiment.

Referring to FIG. 14, FIG. 14 illustrates a dummy toggle (Dummy toggle)and data (Chunk), input through an input/output pin DQ, based on a chipenable signal CE_SIG.

In an embodiment, when the memory device 100 does not operate, a chipenable signal CE_SIG corresponding to the corresponding memory devicemay be output in a high state. However, when the memory device 100 isoperating (e.g., when data is transmitted or received through theinput/output pin DQ), a chip enable signal CE_SIG corresponding to thecorresponding memory device may be output in a low state.

In an embodiment, when data is transmitted or received through theinput/output pin DQ, the total current consumption of the memory device100 may be instantaneously increased or decreased. Therefore, in orderto prevent the total current consumption of the memory device 100 frombeing instantaneously increased, a dummy toggle may be applied to thememory device 100 through the input/output pin DQ. Here, the dummytoggle is a pulse of a certain magnitude that is applied to the memorydevice 100.

That is, when the chip enable signal CE_SIG is in the high state, thedummy toggle may be applied through the input/output pin DQ of thememory device 100, and the total current consumption of the memorydevice 100 may be increased step by step (Warm-up). The magnitude of thedummy toggle may be sequentially increased (1, 2, 3, . . . ).

Consequently, before the memory device starts an operation, the dummytoggle of which magnitude is sequentially increased, is applied to thememory device 100, so that an instantaneous increase in total currentconsumption can be prevented.

When the total current consumption of the memory device 100 isinstantaneously increased through the dummy toggle and then reaches acertain level, the memory device 100 may transmit or receive data.

Although the transmission or reception of the data is ended, i.e., whenit is predicted that the memory device 100 will transmit or receive thedata Chunk, a dummy toggle may be applied to the memory device 100. Thatis, since the memory device 100 immediately starts an operation, thedummy toggle for maintaining the total current consumption to a certainlevel may be applied to the memory device 100. Subsequently, the memorydevice 100 may again transmit or receive data.

In an embodiment, even when the memory device 100 ends the operation, adummy toggle may be applied to the memory device 100 to prevent thetotal current consumption from being instantaneously decreased.

For example, when the chip enable signal CE_SIG is output in the highstate since it is determined that the memory device 100 ends theoperation, dummy toggle may be applied to the memory device 100 and thensequentially interrupted (Warm-down). That is, after the dummy toggle isapplied to the memory device 100 determined to end the operation, themagnitude of the dummy toggle may be sequentially decreased.

Consequently, before the memory device ends the operation, the dummytoggle of which the magnitude is sequentially decreased is applied tothe memory device 100, so that an instantaneous decrease in totalcurrent consumption can be prevented.

FIG. 15 is a diagram illustrating an operation of a memory controller inaccordance with an embodiment of the present disclosure.

FIG. 15 illustrates a sequence in which, when memory devices startoperations, a dummy pulse is applied to channels connecting the memorycontroller to the memory devices.

In step S1401, the memory controller may receive a request from thehost. The request received from the host may be a program request, readrequest or erase request for any one memory device among a plurality ofmemory devices included in the storage device. That is, the memorycontroller may determine which memory device among the plurality ofmemory devices an operation is to be performed on, based on the requestreceived from the host.

In step S1403, the memory controller may determine memory devices inwhich a command is executed, based on the request received from thehost. A number of memory devices in which the command is executed may betwo or more.

In an embodiment, when multiple memory devices simultaneously perform anoperation corresponding to the command, a total current consumption ofthe memory devices may be rapidly increased. Thus, a dummy pulse issequentially applied to the memory devices, so that the total currentconsumption can be gradually increased.

That is, when the memory devices to perform the operation are determinedin response to the request received from host, the dummy pulse may besequentially applied to channels through which the memory controller iscoupled to such memory devices (S1405).

For example, when memory devices to execute a command corresponding tothe request received from the host are determined as first and secondmemory devices, a dummy pulse may be sequentially applied to first andsecond channels through which the memory controller is coupled to thefirst and second memory devices. That is, the dummy pulse is firstapplied to the first or second channel, and then after a set timeelapses from that application of the dummy pulse, the dummy pulse may beapplied to the other channel. Thus, the total current consumption of thememory devices can be prevented from being instantaneously increased.Moreover, right after the operations are performed, the memorycontroller may determine interrupting the applying a dummy pulse.Namely, since the memory devices start to operate, the dummy pulse nolonger needs to be generated for increasing the total currentconsumption progressively.

FIG. 16 is a diagram illustrating an operation of the memory controllerin accordance with an embodiment of the present disclosure.

Referring to FIG. 16, when memory devices end operations, a dummy pulseis applied to, or interrupted in, channels through which the memorycontroller is coupled to the memory devices.

In step S1501, the memory controller may determine a memory device toend an operation among a plurality of memory devices included in thestorage device. The memory device to end the operation among theplurality of memory devices may be determined based on a chip enablesignal. That is, when a chip enable signal in a high state is generated,the memory controller may determine that a memory device correspondingto the chip enable signal is to end the operation.

When memory devices to end operations are determined, a dummy pulse maybe applied to all channels through which the memory controller iscoupled to the determined memory devices, after the determined memorydevices end the operations (S1503). That is, since the memory devicessimultaneously end the operations, the end of the operations of thememory devices may be delayed to prevent a total current consumption ofthe memory devices from being instantaneously decreased.

After the dummy pulse is applied to the channels through which thememory controller is coupled to the memory devices to end theoperations, the dummy pulses applied to the channels may be sequentiallyinterrupted (S1505). That is, after the dummy pulse is applied to thechannels, the memory controller may interrupt the dummy pulse applied toany one channel, and sequentially interrupt the dummy pulses applied tothe other channels after a set time elapses.

Thus, the total current consumption of the memory devices can beprevented from being instantaneously decreased.

FIG. 17 is a diagram illustrating an operation of the memory controllerin accordance with an embodiment of the present disclosure.

Referring to FIGS. 16 and 17, steps S1601 to S1607 correspond to stepS1501. That is, steps S1601 to S1607 may be steps of determining amemory device to end an operation among a plurality of memory devicesthat are operating.

In step S1601, the memory controller may determine whether the generatedchip enable signal is in a high state or low state. The chip enablesignal may correspond to a physical block address PBA. Also, the chipenable signal may be generated for each memory device.

In an embodiment, the memory controller may determine the number ofmemory devices corresponding to a chip enable signal in the high stateamong chip enable signals corresponding to the plurality of memorydevices (S1603). The memory devices corresponding to the chip enablesignal in the high state may be memory devices to end operations.

Subsequently, the memory controller may determine whether a number ofthe memory devices corresponding to the chip enable signal in the highstate is two or more (S1605). When the number of the memory devicescorresponding to the chip enable signal in the high state is not two ormore (N at S1605), i.e., when the number of the memory devicescorresponding to the chip enable signal in the high state is 1, a totalcurrent consumption of the memory devices is not rapidly decreased evenwhen current does not flow in the corresponding memory device. Hence, itis unnecessary for the memory controller to perform an operation forsequentially decreasing the total current consumption.

However, when the number of the memory devices corresponding to the chipenable signal in the high state is two or more (Y at S1605), the totalcurrent consumption of the memory devices may be rapidly decreased, whencurrent does not simultaneously flow in the corresponding memorydevices. Therefore, it is necessary for the memory controller to performan operation for sequentially decreasing the total current consumption.

In an embodiment, in order to sequentially decrease the total currentconsumption, the memory controller may determine command queue levels ofthe memory devices corresponding to the chip enable signal in the highstate (S1607). That is, the memory controller may determine whether adummy pulse is to be applied to, and interrupted in, channels throughwhich the memory controller is coupled to the corresponding memorydevices.

For example, the memory controller may determine whether the dummy pulseis to be applied and interrupted, based on whether the command queuelevels are all “0.”

FIG. 18 is a diagram illustrating an operation of the memory controllerin accordance with an embodiment of the present disclosure.

Referring to FIGS. 16 and 18, steps S1701 to S1707 correspond to stepS1503.

In step S1701, the memory controller may determine whether command queuelevels are all “0.” That is, channels to which a dummy pulse is to beapplied may be determined based on the command queue levels.

In an embodiment, when the command queue levels are not all “0” (N atS1701), the memory controller may determine whether the number of memorydevices of which command queue levels are “0” is two or more (S1703).When the number of memory devices of which command queue levels are “0”is not two or more (N at S1703), i.e., when the number of memory devicesof which command queue levels are “0” is 1, the memory controller mayapply the dummy pulse to a channel coupled to the memory device of whichcommand queue level is not “0” (S1705). That is, the dummy pulse may beapplied to channels coupled to memory devices that currently endoperations but are immediately to perform other operations again. Here,the dummy pulse is applied to the channels at the same time orgradually.

Therefore, current is not consumed in a channel coupled to a memorydevice to end an operation. Since the number of memory devices to endoperations is 1, a total current consumption of the memory devices maynot be rapidly decreased.

When the command queue levels are all “0,” as determined in step S1701(Y) or when the number of memory devices of which command queue levelsare “0” is two or more, as determined in step S1703 (Y), the memorycontroller may apply a dummy pulse to all channels through which thememory controller is coupled to the memory devices to end or suspend theoperations (S1707). That is, since it is determined that all the memorydevices end operations or since it is determined that two or more memorydevices end operations, the dummy pulse may be applied to all channelscoupled to memory devices determined to end operations. Here, the dummypulse is applied to the channels at the same time or gradually.Subsequently, the dummy pulses applied to the channels may besequentially interrupted (S1505).

When the number of memory devices of which command queue levels are “0”is two or more, as determined in step S1703, the dummy pulses may besequentially interrupted in only the channels coupled to the memorydevices of which command queue levels are “0” in step S1505.

Therefore, when the dummy pulses applied to the channels aresequentially interrupted, the total current consumption of the memorydevices may not be rapidly decreased.

FIG. 19 is a diagram illustrating the memory cell array 110 of FIG. 3 inaccordance with an embodiment.

Referring to FIG. 19, the memory cell array 110 may include a pluralityof memory blocks BLK1 to BLKz. Each memory block may have athree-dimensional structure. Each memory block may include a pluralityof memory cells stacked on a substrate. The memory cells are arranged ina +X direction, a +Y direction, and a +Z direction. The structure ofeach memory block will be described in more detail with reference toFIGS. 20 and 21.

FIG. 20 is a circuit diagram illustrating a memory block BLKAa of thememory blocks BLK1 to BLKz of FIG. 3 in accordance with an embodiment.

Referring to FIG. 20, the memory block BLKa may include a plurality ofcell strings CS11 to CS1 m and CS21 to CS2 m. In an embodiment, each ofthe cell strings CS11 to CS1 m and CS21 to CS2 m may be formed in a ‘U’shape. In the memory block BLKa, m cell strings may be arranged in a rowdirection (i.e., the +X direction). In FIG. 20, two cell strings areillustrated as being arranged in a column direction (i.e., the +Ydirection). However, this illustration is made only for convenience ofdescription, and it will be understood that three or more cell stringsmay be arranged in the column direction.

Each of the plurality of cell strings CS11 to CS1 m and CS21 to CS2 mmay include at least one source select transistor SST, first to n-thmemory cells MC1 to MCn, a pipe transistor PT, and at least one drainselect transistor DST.

The select transistors SST and DST and the memory cells MC1 to MCn mayhave similar structures, respectively. In an embodiment, each of theselect transistors SST and DST and the memory cells MC1 to MCn mayinclude a channel layer, a tunneling insulating layer, a charge storagelayer, and a blocking insulating layer. In an embodiment, a pillar forproviding the channel layer may be provided in each cell string. In anembodiment, a pillar for providing at least one of the channel layer,the tunneling insulating layer, the charge storage layer, and theblocking insulating layer may be provided in each cell string.

The source select transistor SST of each cell string is coupled betweenthe common source line CSL and the memory cells MC1 to MCp.

In an embodiment, source select transistors of cell strings arranged inthe same row are coupled to a source select line extending in a rowdirection, and source select transistors of cell strings arranged indifferent rows are coupled to different source select lines. In FIG. 20,source select transistors of the cell strings CS11 to CS1 m in a firstrow are coupled to a first source select line SSL1. Source selecttransistors of the cell strings CS21 to CS2 m in a second row arecoupled to a second source select line SSL2.

In an embodiment, the source select transistors of the cell strings CS11to CS1 m and CS21 to CS2 m may be coupled in common to a single sourceselect line.

The first to n-th memory cells MC1 to MCn in each cell string arecoupled between the source select transistor SST and the drain selecttransistor DST.

The first to n-th memory cells MC1 to MCn may be divided into first top-th memory cells MC1 to MCp and p+1-th to n-th memory cells MCp+1 toMCn. The first to p-th memory cells MC1 to MCp are successively arrangedin a direction opposite to the +Z direction and are coupled in seriesbetween the source select transistor SST and the pipe transistor PT. Thep+1-th to n-th memory cells MCp+1 to MCn are successively arranged inthe +Z direction and are coupled in series between the pipe transistorPT and the drain select transistor DST. The first to p-th memory cellsMC1 to MCp and the p+1-th to n-th memory cells MCp+1 to MCn are coupledto each other through the pipe transistor PT. The gates of the first ton-th memory cells MC1 to MCn of each cell string are coupled to first ton-th word lines WL1 to WLn, respectively.

Respective gates of the pipe transistors PT of the cell strings arecoupled to a pipeline PL.

The drain select transistor DST of each cell string is coupled betweenthe corresponding bit line and the memory cells MCp+1 to MCn. The cellstrings arranged in the row direction are coupled to drain select linesextending in the row direction. Drain select transistors of the cellstrings CS11 to CS1 m in the first row are coupled to a first drainselect line DSL1. Drain select transistors of the cell strings CS21 toCS2 m in the second row are coupled to a second drain select line DSL2.

Cell strings arranged in the column direction may be coupled to bitlines extending in the column direction. In FIG. 20, cell strings CS11and CS21 in a first column are coupled to a first bit line BL1. Cellstrings CS1 m and CS2 m in an m-th column are coupled to an m-th bitline BLm.

Memory cells coupled to the same word line in cell strings arranged inthe row direction form a single page. For example, memory cells coupledto the first word line WL1, among the cell strings CS11 to CS1 m in thefirst row, form a single page. Memory cells coupled to the first wordline WL1, among the cell strings CS21 to CS2 m in the second row, formanother single page. When any one of the drain select lines DSL1 andDSL2 is selected, corresponding cell strings arranged in the directionof a single row may be selected. When any one of the word lines WL1 toWLn is selected, a corresponding single page may be selected from amongthe selected cell strings.

In an embodiment, even bit lines and odd bit lines may be provided inlieu of the first to m-th bit lines BL1 to BLm. Even-number cell stringsof the cell strings CS11 to CS1 m or CS21 to CS2 m arranged in the rowdirection may be coupled to respective even bit lines. Odd-number cellstrings of the cell strings CS11 to CS1 m or CS21 to CS2 m arranged inthe row direction may be coupled to respective odd bit lines.

In an embodiment, at least one of the first to n-th memory cells MC1 toMCn may be used as a dummy memory cell. For example, at least one ormore dummy memory cells may be provided to reduce an electric fieldbetween the source select transistor SST and the memory cells MC1 toMCp. Alternatively, at least one or more dummy memory cells may beprovided to reduce an electric field between the drain select transistorDST and the memory cells MCp+1 to MCn. As the number of dummy memorycells is increased, the reliability in operation of the memory blockBLKa may be increased, while the size of the memory block BLKa may beincreased. As the number of dummy memory cells is reduced, the size ofthe memory block BLKa may be reduced, but the reliability in operationof the memory block BLKa may be reduced.

To efficiently control the at least one dummy memory cells, each of thedummy memory cells may have a required threshold voltage. Before orafter an erase operation on the memory block BLKa is performed, programoperations may be performed on all or some of the dummy memory cells. Inthe case where an erase operation is performed after a program operationhas been performed, the dummy memory cells may have required thresholdvoltages by controlling voltages to be applied to the dummy word linescoupled to the respective dummy memory cells.

FIG. 21 is a circuit diagram illustrating a memory block BLKb of thememory blocks BLK1 to BLKz of FIG. 3, in accordance with an embodiment.

Referring to FIG. 21, the memory block BLKb may include a plurality ofcell strings CS11′ to CS1 m′ and CS21′ to CS2 m′. Each of the cellstrings CS11′ to CS1 m′ and CS21′ to CS2 m′ extends in the +Z direction.Each of the cell strings CS11′ to CS1 m′ and CS21′ to CS2 m′ may includeat least one source select transistor SST, first to n-th memory cellsMC1 to MCn, and at least one drain select transistor DST which arestacked on a substrate (not shown) provided in a lower portion of thememory block BLKb.

The source select transistor SST of each cell string is coupled betweenthe common source line CSL and the memory cells MC1 to MCn. The sourceselect transistors of cell strings arranged in the same row are coupledto the same source select line. Source select transistors of the cellstrings CS11′ to CS1 m′ arranged in a first row may be coupled to afirst source select line SSL1. Source select transistors of the cellstrings CS21′ to CS2 m′ arranged in a second row may be coupled to asecond source select line SSL2. In an embodiment, source selecttransistors of the cell strings CS11′ to CS1 m′ and CS21′ to CS2 m′ maybe coupled in common to a single source select line.

The first to n-th memory cells MC1 to MCn in each cell string arecoupled in series between the source select transistor SST and the drainselect transistor DST. Gates of the first to n-th memory cells MC1 toMCn are respectively coupled to first to n-th word lines WL1 to WLn.

The drain select transistor DST of each cell string is coupled betweenthe corresponding bit line and the memory cells MC1 to MCn. Drain selecttransistors of cell strings arranged in the row direction may be coupledto drain select lines extending in the row direction. Drain selecttransistors of the cell strings CS11′ to CS1 m′ in the first row arecoupled to a first drain select line DSL1. Drain select transistors ofthe cell strings CS21′ to CS2 m′ in the second row may be coupled to asecond drain select line DSL2.

Consequently, the memory block BLKb of FIG. 21 may have an equivalentcircuit similar to that of the memory block BLKa of FIG. 20 except thata pipe transistor PT of FIG. 20 is excluded from each cell string of thememory block BLKb of FIG. 21.

In an embodiment, even bit lines and odd bit lines may be provided inlieu of the first to m-th bit lines BL1 to BLm. Even-number cell stringsamong the cell strings CS11′ to CS1 m′ or CS21′ to CS2 m′ arranged inthe row direction may be coupled to the respective even bit lines, andodd-number cell strings among the cell strings CS11′ to CS1 m′ or CS21′to CS2 m′ arranged in the row direction may be coupled to the respectiveodd bit lines.

In an embodiment, at least one of the first to n-th memory cells MC1 toMCn may be used as a dummy memory cell. For example, at least one ormore dummy memory cells may be provided to reduce an electric fieldbetween the source select transistor SST and the memory cells MC1 toMCn. Alternatively, at least one or more dummy memory cells may beprovided to reduce an electric field between the drain select transistorDST and the memory cells MC1 to MCn. As the number of dummy memory cellsis increased, the reliability in operation of the memory block BLKb maybe increased, while the size of the memory block BLKb may be increased.As the number of dummy memory cells is reduced, the size of the memoryblock BLKb may be reduced, but the reliability in operation of thememory block BLKb may be reduced.

To efficiently control the at least one dummy memory cells, each of thedummy memory cells may have a required threshold voltage. Before orafter an erase operation on the memory block BLKb is performed, programoperations may be performed on all or some of the dummy memory cells. Inthe case where an erase operation is performed after a program operationhas been performed, the dummy memory cells may have required thresholdvoltages by controlling voltages to be applied to the dummy word linescoupled to the respective dummy memory cells.

FIG. 22 is a circuit diagram illustrating a memory block BLKc of thememory blocks BLK1 to BLKz included in the memory cell array 110 of FIG.3, in accordance with an embodiment.

Referring to FIG. 22, the memory block BLKc includes a plurality of cellstrings CS1 to CSm. The plurality of cell strings CS1 to CSm may berespectively coupled to a plurality of bit lines BL1 to BLm. Each of thecell strings CS1 to CSm includes at least one source select transistorSST, first to n-th memory cells MC1 to MCn, and at least one drainselect transistor DST.

The select transistors SST and DST and the memory cells MC1 to MCn mayhave similar structures, respectively. In an embodiment, each of theselect transistors SST and DST and the memory cells MC1 to MCn mayinclude a channel layer, a tunneling insulating layer, a charge storagelayer, and a blocking insulating layer. In an embodiment, a pillar forproviding the channel layer may be provided in each cell string. In anembodiment, a pillar for providing at least one of the channel layer,the tunneling insulating layer, the charge storage layer, and theblocking insulating layer may be provided in each cell string.

The source select transistor SST of each cell string is coupled betweenthe common source line CSL and the memory cells MC1 to MCn.

The first to n-th memory cells MC1 to MCn in each cell string arecoupled between the source select transistor SST and the drain selecttransistor DST.

The drain select transistor DST of each cell string is coupled betweenthe corresponding bit line and the memory cells MC1 to MCn.

Memory cells coupled to the same word line may form a single page. Thecell strings CS1 to CSm may be selected by selecting the drain selectline DSL. When any one of the word lines WL1 to WLn is selected, acorresponding single page may be selected from among the selected cellstrings.

In an embodiment, even bit lines and odd bit lines may be provided inlieu of the first to m-th bit lines BL1 to BLm. Even-number cell stringsof the cell strings CS1 to CSm may be coupled to the respective even bitlines, and odd-number cell strings may be coupled to the respective oddbit lines.

As illustrated in FIGS. 19 to 21, the memory cell array 110 of thememory device 100 may be formed of a memory cell array having athree-dimensional structure. Furthermore, as illustrated in FIG. 22, thememory cell array 110 of the memory device 100 may be formed of a memorycell array having a two-dimensional structure.

FIG. 23 is a diagram illustrating signals which are exchanged between amemory controller 200 and a memory device 100 in accordance with anembodiment. Referring to FIG. 23, the memory controller 200 and thememory device 100 may exchange one or more signals DQ[7:0] eachindicating a command, data, and an address through a data pad.Furthermore, the memory controller 200 and the memory device 100 mayexchange a data strobe signal DQS through a data strobe pad. The memorydevice 100 may receive a chip enable signal CE #, a write enable signalWE #, a read enable signal RE #, an address latch enable signal ALE, acommand latch enable signal CLE, a write protection signal WP #, etc.Also, the memory device 100 may output a ready/busy signal RB through aready/busy pad.

To perform a program operation of the memory device 100, the memorycontroller 200 may output a data strobe signal DQS through the datastrobe pad. In synchronization with the data strobe signal DQS outputthrough the data strobe pad, the memory controller 200 may output aprogram command, an address, and program data through the data pad.

To perform a read operation of the memory device 100, the memorycontroller 200 may output a read enable signal RE # through a readenable pad. In response to the read enable signal RE #, the memorydevice 100 may output a data strobe signal DQS. In synchronization withthe data strobe signal DQS, the memory device 100 may output read datathrough the data pad.

During a program operation of the memory device 100, the memorycontroller 200 may output a data strobe signal DQS to the memory device100, and output program data to the memory device 100 through the datapad. During a read operation of the memory device 100, the memory device100 may output a data strobe signal DQS to the memory controller 200,and output read data to the memory controller 200 through the data pad.

Referring back to FIG. 5, a plurality of memory devices 100_1 to 100_4are coupled to a plurality of channels CH1 to CH4, respectively, inaccordance with an embodiment.

In the memory controller 200 according to an embodiment of the presentdisclosure, when each of the memory devices 100_1 to 100_4 starts anoperation, an initial frequency of a clock signal output may becontrolled based on an idle time of each of the memory devices 100_1 to100_4. In an embodiment, the clock signal that is output from the memorycontroller 200 may be a read enable signal RE # which is output during aread operation, or a data strobe signal DQS which is output during aprogram operation. In the memory controller 200 in accordance with anembodiment of the present disclosure, if the idle time of a memorydevice 100_1, 100_2, 100_3, or 100_4 exceeds a threshold time, a clocksignal to be output to the memory device may be generated based on aninitial frequency (or initial operation frequency) less than a normalfrequency during an initial frequency scaling period. In an embodiment,when the idle time of a memory device 100_1, 100_2, 100_3, or 100_4exceeds a threshold time, the memory controller 200 may generate a clocksignal having an initial frequency during an initial frequency scalingperiod, the initial frequency being less than a normal frequency. If theinitial frequency scaling period has passed and the process enters anormal operation period, the memory controller 200 may generate clocksignals to be output to the memory devices 100_1 to 100_4 based on thenormal frequency. Therefore, if the plurality of memory devices 100_1 to100_4 start operations substantially at the same time, the entirecurrent consumption of the storage device 50 may be prevented fromrapidly increasing by reducing an initial operation frequency of each ofthe clock signals output from the memory devices 100_1 to 100_4 duringthe initial frequency scaling period compared to the normal frequency.

Referring back to FIG. 6, a plurality of memory devices 100_1 to 100_8are coupled to a plurality of channels CH1 to CH4 in accordance with anembodiment.

In the memory controller 200 in accordance with an embodiment of thepresent disclosure, when each of the memory devices 100_1 to 100_8starts an operation, an initial frequency of a clock signal output maybe controlled based on an idle time of each of the memory devices 100_1to 100_8. In an embodiment, the clock signal that is output from thememory controller 200 may be a read enable signal RE # which is outputthrough the read enable pad during a read operation, or a data strobesignal DQS which is output through the DQS pad during a programoperation. In the memory controller 200 in accordance with an embodimentof the present disclosure, if the idle time of one of the memory devices100_1 to 100_8 exceeds a threshold time, a clock signal to be output tothe memory device may be generated based on an initial frequency lessthan a normal frequency during an initial frequency scaling period. Ifthe initial frequency scaling period has passed and the process enters anormal operation period, the memory controller 200 may generate clocksignals to be output to the memory devices 100_1 to 100_8 based on thenormal frequency. Therefore, if the plurality of memory devices 100_1 to100_8 start operations substantially at the same time, the entirecurrent consumption of the storage device 50 may be prevented fromrapidly increasing by reducing the initial operation frequency of eachof the clock signals output from the memory devices 100_1 to 100_8during the initial frequency scaling period compared to the normalfrequency.

FIG. 24 is a diagram for describing a change in entire currentconsumption when memory devices coupled to a plurality of channels startoperations substantially at the same time in accordance with anembodiment. Referring to FIG. 24, if a plurality of memory devices startor end operations substantially at the same time, a noise may occur on avoltage source Vsource.

For example, the plurality of memory devices may remain idle until timet0. In the idle state, a total current I_(TOT) that is consumed in astorage device (e.g., the storage device 50 in FIG. 1) may be maintainedat a relatively low idle state current I_(IDLE). At a first time t0, theplurality of memory devices may start operations substantially at thesame time. As the plurality of memory devices start the operationssubstantially at the same time, the total current I_(TOT) that isconsumed in the storage device 50 during a period from the first time t0to a second time t1 may rapidly increase from the idle state currentI_(IDLE) to a peak current I_(PK). The total current I_(TOT) that hasincreased to the peak current I_(PK) at the second time t1 may bereduced to a steady state current I_(SS) from the second time t1 to athird time t2 as the operation of the storage device 50 is stabilized.The storage device 50 is in a transient state during a period from thefirst time t₀ to the third time t2.

From the third time t2 after the transient state has been terminated,the storage device 50 may operate in a steady state. The total currentI_(TOT) that is consumed by the storage device 50 in the steady statemay be stably maintained at the steady state current I_(SS).

As illustrated in FIG. 24, in the case where the plurality of memorydevices included in the storage device 50 start operations substantiallyat the same time, the total current I_(TOT) that is consumed by thestorage device 50 in the transient state may rapidly increase to thepeak current I_(PK). If each of the plurality of memory devices operatesat a relatively high speed, the peak current I_(PK) may have arelatively large magnitude.

In a memory controller (e.g., the memory controller 200 in FIG. 1) inaccordance with an embodiment of the present disclosure, when a memorydevice in the storage device 50 starts an operation, an initialfrequency of a clock signal output may be controlled based on an idletime of the memory device. In the memory controller 200 in accordancewith an embodiment of the present disclosure, if the idle time of thememory device exceeds a threshold time, a clock signal to be output tothe memory device may be generated based on an initial frequency lessthan a normal frequency during an initial frequency scaling period. Ifthe initial frequency scaling period has passed and the process enters anormal operation period, the memory controller 200 may generate a clocksignal to be output to the memory device based on the normal frequency.Therefore, even if a plurality of memory devices start operationssubstantially at the same time, the entire current consumption of thestorage device 50 may be prevented from rapidly increasing by reducingthe initial operation frequency of the clock signal from the memorydevice during the initial frequency scaling period compared to thenormal frequency.

FIG. 25 is a block diagram illustrating a memory controller 200 inaccordance with an embodiment of the present disclosure.

Referring to FIG. 25, the memory controller 200 in accordance with anembodiment of the present disclosure may include an idle time monitor260 and a clock signal generator 270. The idle time monitor 260 maymonitor an idle time t_(IDLE) of the memory device included in a storagedevice (e.g., the storage device 50 in FIG. 1) and output it to theclock signal generator 270. For example, the idle time monitor 260 maygenerate a signal indicative the idle time t_(IDLE) of the memory deviceand output the generated signal to the clock signal generator 270. Theclock signal generator 270 may generate a read enable signal RE # or adata strobe signal DQS based on the received idle time t_(IDLE).

FIG. 26 is a block diagram illustrating the clock signal generator 270of FIG. 25 in accordance with an embodiment of the present disclosure.

Referring to FIG. 26, the clock signal generator 270 may include afrequency controller 231, a read enable signal generator 233, and a datastrobe signal generator 235.

The frequency controller 231 may receive an idle time t_(IDLE) of thememory device and control a frequency of a clock signal to be output tothe memory device. In other words, the frequency controller 231 maygenerate a frequency FR1 or FR2 for generating a clock signal andtransmit the frequency FR1 or FR2 to the read enable signal generator233 or the data strobe signal generator 235. For example, the frequencycontroller 231 may generate a first signal indicative of a firstfrequency FR1 and transmit the first signal to the read enable signalgenerator 233, or may generate a second signal indicative of a secondfrequency FR2 and transmit the second signal to the data strobe signalgenerator 235.

In more detail, during a read operation of the memory device, the memorycontroller 200 may generate a read enable signal RE #. In this case, thefrequency controller 231 may control the frequency FR1 for generatingthe read enable signal RE # based on the idle time t_(IDLE). During aprogram operation of the memory device, the memory controller 200 maygenerate a data strobe signal DQS. In this case, the frequencycontroller 231 may control the frequency FR2 for generating the datastrobe signal DQS based on the idle time t_(IDLE).

The read enable signal generator 233 may generate a read enable signalRE # based on the frequency FR1 that is controlled by the frequencycontroller 231. The data strobe signal generator 235 may generate a datastrobe signal DQS based on the frequency FR2 that is controlled by thefrequency controller 231.

An operation of the memory controller 200 in accordance with anembodiment of the present disclosure will be described below in detailwith reference to FIG. 27.

FIG. 27 is a flowchart for describing a method of operating a memorycontroller (e.g., the memory controller 200 in FIG. 25) in accordancewith an embodiment of the present disclosure.

Referring to FIG. 27, at step S110, an operation of a memory device thatis idle may be determined. At step S110, it may be determined that anoperation of at least one of the first to fourth memory devices 100_1 to100_4 illustrated in FIG. 5 starts. At step S110, it may be determinedthat an operation for at least one of the first to eighth memory devices100_1 to 100_8 illustrated in FIG. 6 starts.

At step S120, an idle time t_(IDLE) of a memory device that has beendetermined to start the operation may be determined. The idle timet_(IDLE) of the memory device may correspond to a time interval betweena first time when a previous operation of the corresponding memorydevice ends to a second time when a subsequent operation thereof starts.Step S120 may be performed by the idle time monitor 260 of FIG. 25.

At step S130, it is determined whether the determined idle time (or idletime interval) t_(IDLE) is greater than a threshold time (or a thresholdtime interval) t_(THR). The threshold time t_(THR) may be a value thatis determined depending on the design or a result of simulation. If thedetermined idle time t_(IDLE) is greater than the threshold timet_(THR), it may indicate that the memory device has been idle for arelatively long time. When the memory device that has been idle for arelatively long time starts an operation, there is high possibility forother memory devices to also start operations substantially at the sametime.

Therefore, if the idle time t_(IDLE) of the memory device is greaterthan the threshold time t_(THR) (YES at step S130), a clock signalneeded for the operation may be generated based on an initial frequencyFR_(IS) (at step S140). Hence, during an initial operation period of thememory device, the clock signal may be generated based on the initialfrequency FR_(IS). For example, the generated clock signal may have theinitial frequency FR_(IS) during the initial operation period. After theinitial operation period of the memory device, a clock signal may begenerated based on a normal frequency FR_(NM) (at step S150). Hence,during a normal operation period after the initial operation period ofthe memory device, the clock signal may be generated based on the normalfrequency FR_(NM). For example, the generated clock signal may have thenormal frequency FR_(NM) during a normal operation period. The initialfrequency FR_(IS) may be a value less than the normal frequency FR_(NM).Therefore, if the idle time t_(IDLE) of the memory device is greaterthan the threshold time t_(THR) (YES at step S130), the initialoperation may be performed based on the initial frequency FR_(IS) havinga value less than the normal frequency FR_(NM), and the normal operationmay be thereafter performed based on the normal frequency FR_(NM). Theoperation frequency of the memory device may have great influence oncurrent consumption. Hence, the peak current I_(PK) that occurs in atransient period t0 to t2 of FIG. 24 may be reduced.

If the determined idle time t_(IDLE) is equal to or less than thethreshold time t_(THR), it may indicate that the memory device has beenidle for a relatively short time. If the memory device that has beenidle for a relatively short time starts an operation, there is highpossibility for other memory devices each to keep performing currentoperations or remain in the idle state, rather than starting a newoperation. Therefore, if the idle time t_(IDLE) of the memory device isequal to or less than the threshold time t_(THR) (NO at step S130), theprocess may directly enter the normal operation period without theinitial operation period. Therefore, in this case, step S150 may bedirectly performed without performing step S140. Hence, the operatingspeed of the memory device may not be significantly reduced because ofan unnecessary initial operation.

FIGS. 28A and 28B are timing diagrams for describing a method ofoperating a memory controller (e.g., the memory controller 200 in FIG.25) in accordance with an embodiment of the present disclosure. AlthoughFIGS. 28A and 28B illustrate read enable signals RE # as examples of aclock signal, embodiments of the present disclosure are not limitedthereto. For example, a data strobe signal DQS which is generated by thememory controller 200 may also be illustrated in the same manner asillustrated in FIGS. 28A and 28B.

FIG. 28A shows a read enable signal RE # that is generated in a firstcase CASE I where the idle time t_(IDLE) is equal to or less than thethreshold time t_(THR) as a result of the determination at step S130 ofFIG. 27. The read enable signal RE # that has swung based on the normalfrequency FR_(NM) during a previous operation period may not swingduring an idle period. Since the idle time t_(IDLE) in the idle periodis less than the threshold time t_(THR), the idle period may end and anormal operation period may directly start. Specifically, the idle timet_(IDLE) may correspond to a duration of the idle period. During thenormal operation period, the read enable signal RE # may be generatedbased on the normal frequency FR_(NM) at step S150 of FIG. 27. Duringthe normal operation period, a data transfer operation may be performedbetween a memory device and a memory controller. In more detail, since aclock signal illustrated in FIG. 28A is a read enable signal RE #, readdata may be transmitted from the memory device to the memory controllerduring the normal operation period.

FIG. 28B shows a read enable signal RE # that is generated in a secondCASE II where the idle time t_(IDLE) is greater than the threshold timet_(THR) as a result of the determination at step S130. The read enablesignal RE # that has swung based on the normal frequency FR_(NM) duringa previous operation period may not swing during an idle period. Sincethe idle time t_(IDLE) in the idle period is greater than the thresholdtime t_(THR), the idle period may end and an initial operation period,i.e., an initial frequency scaling period, may start. During the initialfrequency scaling period, the read enable signal RE # may be generatedbased on a scaled initial frequency FR_(IS) at step S140 of FIG. 27. Theinitial frequency FR_(IS) may have a value less than the normalfrequency FR_(NM). Hence, during the initial frequency scaling period, aclock signal, e.g., a read enable signal RE #, may swing at a relativelylow speed.

If the initial operation period, i.e., the initial frequency scalingperiod, is terminated, the normal operation period may start. During thenormal operation period, the read enable signal RE # may be generatedbased on the normal frequency FR_(NM) at step S150. During the initialfrequency scaling period and the normal operation period, a datatransfer operation may be performed between the memory device and thememory controller. In more detail, since a clock signal illustrated inFIG. 28B is a read enable signal RE #, read data may be transmitted fromthe memory device to the memory controller during the initial frequencyscaling period and the normal operation period.

As illustrated in FIGS. 28A and 28B, when the memory device 100 startsan operation, the memory controller 200 in accordance with an embodimentof the present disclosure may control the initial frequency of a clocksignal output based on the idle time t_(IDLE) of the memory device 100.In the memory controller 200 in accordance with an embodiment of thepresent disclosure, if the idle time t_(IDLE) of the memory device 100exceeds the threshold time t_(THR), a clock signal to be output to thememory device 100 may be generated based on an initial frequency FR_(IS)less than the normal frequency FR_(NM) during the initial frequencyscaling period. If the initial frequency scaling period has passed andthe process enters a normal operation period, the memory controller maygenerate a clock signal to be output to the memory devices 100 based onthe normal frequency FR_(NM). Therefore, if the plurality of memorydevices 100_1 to 100_8 start operations substantially at the same time,the entire current consumption of the storage device 50 may be preventedfrom rapidly increasing by reducing the initial operation frequency.

Referring to FIG. 28B, the second case CASE II where the initialfrequency FR_(IS) used during the initial frequency scaling period is aninvariable constant. In other words, during the initial frequencyscaling period of FIG. 28B, the frequency of the read enable signal RE #may remain substantially constant. However, various embodiments of thepresent disclosure are not limited thereto. For example, the initialfrequency FR_(IS) that is used during the initial frequency scalingperiod may vary over time. For instance, the initial frequency FR_(IS)that is used during the initial frequency scaling period may begradually increased over time. Embodiments of controlling the frequencyof a clock signal generated during the initial frequency scaling periodwill be described with reference to FIGS. 29 to 32.

FIG. 29 is a flowchart illustrating step S140 of FIG. 27 in accordancewith an embodiment of the present disclosure. FIG. 29 illustrates anexample of a method of controlling the frequency of a clock signalgenerated during an initial frequency scaling period. In other words,FIG. 29 illustrates a method of controlling the initial frequencyFR_(IS) according to an embodiment.

Referring to FIG. 29, a frequency controller (e.g., the frequencycontroller 231 in FIG. 26) may set the initial frequency FR_(IS) to abasic frequency FR0 as an initial value at step S210. The basicfrequency FR0 may be a constant value and be less than the normalfrequency FR_(NM). Thereafter, at step S220, a clock signal isgenerated. Step S220 may be performed by a read enable signal generator(e.g., the read enable signal generator 233 in FIG. 26) or a data strobesignal generator (e.g., the data strobe signal generator 235 in FIG.26). At step S220, a clock signal corresponding to one cycle may begenerated. The clock signal may be a read enable signal RE # or a datastrobe signal DQS.

After the clock signal corresponding to one cycle has been generated atstep S220, it is determined whether clock signals have been generated bya given number of unit clocks at step S230. The number of unit clocksmay indicate the number of cycles of clocks that are sequentiallygenerated by the same initial frequency FR_(IS). In an embodiment, theclock signal is generated based on the same initial frequency FR_(IS)until the number of cycles of the generated clock signal reaches a givennumber. For example, in the case where the number of unit clocks isthree, clock signals having the same frequency may be generated duringthree cycles. The number of unit clocks may be set to various values, asneeded.

As a result of the determination at step S230, if clock signals are notgenerated by the number of unit clocks (NO at step S230), the processmay return to step S220 without changing the initial frequency FR_(IS)so that a clock signal corresponding to one cycle is generated again. Ifthe foregoing is repeated and clock signals are thus generated by thenumber of unit clocks (YES at step S230), the initial frequency FR_(IS)is increased at step S240. At step S240, the initial frequency FS_(IS)may increase by various increments.

After the initial frequency FR_(IS) is increased, it may be determinedwhether the initial frequency FR_(IS) has reached the normal frequencyFR_(NM) at step S250. If the initial frequency FR_(IS) has reached thenormal frequency FR_(NM) (YES at step S250), this may indicate that theinitial frequency scaling period has been terminated. Therefore,referring back to FIG. 27, step S140 may end, and the process mayproceed to step S150 so that the normal operation period may start.

If the initial frequency FR_(IS) has not reached the normal frequencyFR_(NM) (NO at step S250), the process may return to step S220 so that aclock signal corresponding to the increased initial frequency FR_(IS)may be generated.

FIGS. 30A and 30B are timing diagrams for describing the process of FIG.29 according to embodiments.

FIG. 30A illustrates a method of controlling the initial frequencyFR_(IS) in the case where the number of unit clocks is two. If theinitial frequency scaling period starts, the initial frequency FR_(IS)may be set to the basic frequency FR0, at step S210. Hence, during afirst unit clock period UC1, a clock signal (e.g., a read enable signalRE #) corresponding to two cycles may be generated based on the basicfrequency FR0.

If the clock signal corresponding to two cycles is generated, thefrequency controller 231 may increase the initial frequency FR_(IS) as aresult of the determination at step S230. Hence, during a second unitclock period UC2, a clock signal corresponding to two cycles may begenerated based on the increased initial frequency FR_(IS). Likewise,during a third unit clock period UC3, a clock signal may be generatedbased on a further increased initial frequency FR_(IS). During a fourthunit clock period UC4, a clock signal may be generated based on afurther increased initial frequency FR_(IS). In the case where thefourth unit clock period ends and the initial frequency FR_(IS) that hasincreased by step S240 has reached the normal frequency FR_(NM), theinitial frequency scaling period may end and the process may enter thenormal operation period.

FIG. 30B illustrates a method of controlling the initial frequencyFR_(IS) in the case where the number of unit clocks is one. Since thenumber of unit clocks is one, the read enable signal RE # may begenerated based on the initial frequency FR_(IS) that increases for eachperiod. In other words, since the unit clock period in FIG. 30B is aclock period corresponding to one cycle, the initial frequency FR_(IS)may increase at each time when the clock signal completes one cycle.

Although FIGS. 30A and 30B illustrate examples in which the numbers ofunit clocks are two and one, respectively, embodiments of the presentdisclosure are not limited thereto. For example, an embodiment in whichthe number of unit clocks is 3 or more may also fall within the boundsof the present disclosure.

FIG. 31 is a flowchart illustrating step S140 of FIG. 27 according to anembodiment. FIG. 31 illustrates an example of a method of controlling afrequency of a clock signal generated during an initial frequencyscaling period.

Referring to FIG. 31, a frequency controller (e.g., the frequencycontroller 231 in FIG. 26) may set the initial frequency FR_(IS) to abasic frequency FR0 as an initial value at step S310. The basicfrequency FR0 may be a constant value and be less than the normalfrequency FR_(NM). Thereafter, at step S320, a clock signal isgenerated. Step S320 may be performed by a read enable signal generator(e.g., the read enable signal generator 233 in FIG. 26) or a data strobesignal generator (e.g., the data strobe signal generator 235 in FIG.26). At step S320, a clock signal corresponding to one cycle may begenerated. The clock signal may be a read enable signal RE # or a datastrobe signal DQS.

After the clock signal corresponding to one cycle has been generated atstep S320, it is determined whether a clock signal has been generatedduring a unit time (or unit time interval) at step S330. The unit timemay indicate the time it takes to generate a clock signal having thesame initial frequency FR_(IS). For example, the unit time may be a timeinterval during which the clock signal is generated to have the sameinitial frequency FR_(IS) for a given number of periods. The unit timemay be set to various values, as needed.

As a result of the determination at step S330, if a duration duringwhich the clock signal has been generated is shorter than the unit time(NO at step S330), the process may return to step S320 without changingthe initial frequency FR_(IS) so that a clock signal corresponding toone cycle is generated again. For example, when the duration duringwhich the clock signal has been generated is shorter than the unit time,the process continues to generate the clock signal during a next cyclewhile keeping the initial frequency FR_(IS). The foregoing is repeated,and a clock signal is generated based on the same initial frequencyFR_(IS) until it reaches the unit time. For example, the processcontinues to generate the clock signal having the same initial frequencyFR_(IS) until the duration during which the clock signal has beengenerated reaches the unit time.

If a clock signal is generated during the unit time (YES at step S330),the initial frequency value FR_(IS) is increased, at step S340. At stepS340, the initial frequency FSIS may increase by various increments.

After the initial frequency FR_(IS) has increased, it is determinedwhether an initial operation time has passed at step S350. The initialoperation time may be a predetermined fixed time and be used todetermine the initial frequency scaling period. If the initial operationtime has passed (YES at step S350), this may indicate that the initialfrequency scaling period has ended. Therefore, referring back to FIG.27, step S140 may end, and the process may proceed to step S150 so thatthe normal operation period may start.

If the initial operation time has not yet passed (NO at step S350), theprocess may return to step S320 so that a clock signal corresponding tothe increased initial frequency FR_(IS) is generated.

FIG. 32 is a timing diagram for describing the process in FIG. 31according to an embodiment.

Referring to FIG. 32, there are illustrated a unit time UT and aninitial operation time IT. During the unit time UT, the initialoperation frequency FR_(IS) may remain substantially constant. Each timethe unit time UT passes, the initial operation frequency FR_(IS) isincreased. If the initial operation time IT passes, the initialfrequency scaling period ends, and the normal operation period starts.

Although FIGS. 29 to 32 illustrate embodiments of step S140 ofgenerating a clock signal based on the initial frequency FR_(IS),embodiments of the present disclosure are not limited thereto.Therefore, during the initial frequency scaling period, the initialfrequency FR_(IS) may be controlled not only by the methods described inthe embodiments of FIGS. 29 to 32 but also by various methods. Asdescribed with reference to FIGS. 29 to 32, the initial frequencyFR_(IS) may be controlled such that it is gradually increased during theinitial frequency scaling period. Referring back to FIG. 30A, the readenable signal RE # has a first initial frequency during the first unitclock period UC1, a second initial frequency during the second unitclock period UC2, a third initial frequency during the third unit clockperiod UC3, and a fourth initial frequency during the fourth unit clockperiod UC4. In an embodiment, the second initial frequency is a firstgiven times as great as the first initial frequency, the third initialfrequency is a second given times as great as the second initialfrequency, and the fourth initial frequency is a third given times asgreat as the third initial frequency. For example, each of the first,second, and third given times may be in a range from 1.1 times to 5times. The initial frequency FR_(IS) that is controlled during theinitial frequency scaling period may have a value that is always lessthan the normal frequency FR_(NM).

FIG. 33 is a flowchart illustrating step S140 of FIG. 27 according to anembodiment.

Referring to FIG. 33, step S140 of generating a clock signal needed toperform an operation based on the initial frequency FR_(IS) illustratedin FIG. 27 may include step S141 of generating a clock signal based on afirst initial frequency FR_(IS1) less than the normal frequency FR_(NM),and the step S143 of generating a clock signal based on a second initialfrequency FR_(IS2) less than the normal frequency FR_(NM) and greaterthan the first initial frequency FR_(IS1).

Referring to FIGS. 27B, 30A, 30B, and 32, the initial frequency scalingperiod may be set to a single period. However, in a method of operatingthe memory controller in accordance with an embodiment of the presentdisclosure, the initial frequency scaling period may include two or moreperiods. Hereinafter, the embodiment of FIG. 33 will be described withreference to FIG. 34 together.

FIG. 34 is a timing diagram for describing the process illustrated inFIG. 33 according to an embodiment.

FIG. 34 shows a read enable signal RE # that is generated in the casewhere the idle time t_(IDLE) is greater than the threshold time t_(THR)as a result of the determination at step S130 of FIG. 27. The readenable signal RE # that has swung based on the normal frequency FR_(NM)during a previous operation period may not swing during an idle period.Since the idle time t_(IDLE) in the idle period is greater than thethreshold time t_(THR), the idle period ends and an initial operationperiod, i.e., an initial frequency scaling period, starts. During aninitial frequency scaling period including a first initial frequencyscaling period and a second initial frequency scaling period, the readenable signal RE # may be generated based on scaled first and secondinitial frequencies FR_(IS1) and FR_(IS2) at step S140 of FIG. 27.During the first initial frequency scaling period, the second initialfrequency scaling period, and a normal operation period, a data transferoperation may be performed between a memory device and a memorycontroller. In more detail, since a clock signal illustrated in FIG. 34is a read enable signal RE #, read data may be transmitted from thememory device to the memory controller during the first initialfrequency scaling period, the second initial frequency scaling period,and the normal operation period.

In an embodiment illustrated in FIG. 34, the initial frequency scalingperiod may include a first initial frequency scaling period and a secondinitial frequency scaling period. During the first initial frequencyscaling period, a read enable signal RE # may be generated based on thefirst initial frequency FR_(IS1) at step S141. The first initialfrequency FR_(IS1) may be a value less than the normal frequencyFR_(NM). During the second initial frequency scaling period, a readenable signal RE # may be generated based on the second initialfrequency FR_(IS2) at step S143. The second initial frequency FR_(IS2)may have a value less than the normal frequency FR_(NM) and greater thanthe first initial frequency FR_(IS1).

In an embodiment, the first initial frequency FR_(IS1) may have aconstant value. In this case, during the first initial frequency scalingperiod, the read enable signal RE # may be generated based on a constantfrequency less than the normal frequency FR_(NM). However, embodimentsof the present disclosure are not limited thereto. For example, thefirst initial frequency FR_(IS1) may have a value that is graduallyincreased during the first initial frequency scaling period.

In an embodiment, the second initial frequency FR_(IS2) may have a valuethat is gradually increased during the second initial frequency scalingperiod. In this case, the read enable signal RE # based on the secondinitial frequency FR_(IS2) may be generated in the same manner asdescribed with reference to FIGS. 29 to 32. However, embodiments of thepresent disclosure are not limited thereto. For example, the secondinitial frequency FR_(IS2) may have a constant value during the secondinitial frequency scaling period.

If the initial operation period including the first and second initialfrequency scaling periods is terminated, the normal operation period maystart. During the normal operation period, the read enable signal RE #may be generated based on the normal frequency FR_(NM) at step S150 ofFIG. 27.

As illustrated in FIGS. 33 and 34, when the memory device 100 starts anoperation, the memory controller 200 in accordance with an embodiment ofthe present disclosure may control the initial frequency of a clocksignal output based on the idle time t_(IDLE) of the memory device 100.In the memory controller 200 in accordance with an embodiment of thepresent disclosure, if the idle time t_(IDLE) of the memory device 100exceeds the threshold time t_(THR), a clock signal to be output to thememory device 100 may be generated based on the first and second initialfrequencies FR_(IS1) and FR_(IS2) that are less than the normalfrequency FR_(NM) during the first and second initial frequency scalingperiods. If the initial frequency scaling period has passed and theprocess enters a normal operation period, the memory controller 200 maygenerate a clock signal to be output to the memory devices 100 based onthe normal frequency FR_(NM). Therefore, if the plurality of memorydevices 100_1 to 100_8 start operations substantially at the same time,the entire current consumption of the storage device 50 may be preventedfrom rapidly increasing by reducing the initial operation frequency.

FIG. 35 is a flowchart illustrating a method of operating a memorycontroller in accordance with an embodiment of the present disclosure.FIG. 36 is a diagram for describing a method of determining an idle timeat steps S410 and S420 of FIG. 35 according to an embodiment. Referringto FIGS. 35 and 36 together, a frequency scaling operation may beperformed based on an idle time of one or more memory devices other thana memory device that starts an operation. Hereinafter, description willbe made with reference to FIGS. 35 and 36 together.

Referring to FIGS. 35 and 36, at step S410, an operation of a memorydevice selected from among a plurality of memory devices 100_1 to 100_4coupled to respective different channels CH1 to CH4 may be determined.Here, the selected memory device may be idle. Referring to FIG. 36,there is illustrated an example in which, at step S410, the first memorydevice 100_1 of the first to fourth memory devices 100_1 to 100_4 is theselected memory device. In FIG. 36, idle times of the first to fourthmemory devices 100_1 to 100_4 are illustrated as being respectivelyfirst to fourth idle times t_(IDLE)_1 to t_(IDLE)_4. According to theembodiment illustrated in FIGS. 27 to 28B, the idle time t_(IDLE) atstep S120 of FIG. 27 may be determined to be the first idle timet_(IDLE)_1 of the first memory device 100_1 that is the selected memorydevice. According to the embodiment of FIGS. 35 and 36, the idle timet_(IDLE) may be determined based on an idle time of the unselectedmemory devices rather than the selected memory device. Since theselected memory device 100_1 has been idle, the first idle timet_(IDLE)_1 may have a value other than 0. If any one memory device ofthe second to fourth memory devices 100_2 to 100_4 is in operation, theidle time of the operating memory device may be determined to be 0.

At step S420, an idle time (or an idle time interval) t_(IDLE) of memorydevices including at least one unselected memory device among theplurality of memory devices may be determined. The unselected memorydevice may be a memory device other than the selected memory device. InFIG. 36, the at least one unselected memory device may include second tofourth memory devices 100_2 to 100_4. At step S420, an idle timet_(IDLE) of memory devices including at least one memory device amongthe second to fourth memory devices 100_2 to 100_4 may be determined.

In an embodiment, the idle time t_(IDLE) at step S420 may be determinedto be any one idle time among the second to fourth idle times t_(IDLE)_2to t_(IDLE)_4.

In an embodiment, the idle time t_(IDLE) at step S420 may be determinedto be the sum of two idle times among the first to fourth idle timest_(IDLE)_1 to t_(IDLE)_4.

In an embodiment, the idle time t_(IDLE) at step S420 may be determinedto be the sum of three idle times among the first to fourth idle timest_(IDLE)_1 to t_(IDLE)_4.

In an embodiment, the idle time t_(IDLE) at step S420 may be determinedto be the sum of all of the first to fourth idle times t_(IDLE)_1 tot_(IDLE)_4.

FIG. 37 is a flowchart illustrating a method of operating a memorycontroller in accordance with an embodiment of the present disclosure.FIG. 38 is a diagram for describing a method of determining an idle timeat steps S510 and S520 of FIG. 37 according to an embodiment. Referringto FIGS. 37 and 38 together, a frequency scaling operation may beperformed based on an idle time of memory devices other than a memorydevice that starts an operation. Hereinafter, description will be madewith reference to FIGS. 37 and 38 together. FIG. 38 shows an examplewhere two memory devices are coupled to each channel. In otherembodiments, three or more memory devices may be coupled to eachchannel. In the embodiment shown in FIG. 38, the first memory device100_1 is coupled to the first channel CH1 through a first way WAY1 andthe second memory device 100_2 is coupled to the first channel CH1through a second way WAY2. The first and second memory devices 100_1 and100_2 may be coupled to the memory controller 200 through the firstchannel CH1. The third memory device 100_2 is coupled to the secondchannel CH2 through a third way WAY3, and the fourth memory device 100_4is coupled to the second channel CH2 through a fourth way WAY4. Hence,the third and fourth memory devices 100_3 and 100_4 may be coupled tothe memory controller 200 through the second channel CH2.

Referring to FIGS. 37 and 38, at step S510, an operation of a memorydevice selected from among the plurality of memory devices 100_1 to100_8 coupled to the plurality of channels CH1 to CH4 and the respectivedifferent ways WAY1 to WAY8 may be determined. Here, the selected memorydevice may be idle. Referring to FIG. 38, there is illustrated anexample in which, at step S510, the first memory device 100_1 of thefirst to eighth memory devices 100_1 to 100_8 is the selected memorydevice. In FIG. 38, idle times of the first to eighth memory devices100_1 to 100_8 are illustrated as being respectively first to eighthidle times t_(IDLE)_1 to t_(IDLE)_8. According to the embodimentillustrated in FIGS. 27 to 28B, the idle time t_(IDLE) at step S120 ofFIG. 27 may be determined to be the first idle time t_(IDLE)_1 of thefirst memory device 100_1 that is the selected memory device. Accordingto the embodiment of FIGS. 37 and 38, the idle time t_(IDLE) may bedetermined based on an idle time of an unselected memory device that iscoupled to the same channel as that of the selected memory device andcoupled to a way different from that of the selected memory device.Since the selected memory device 100_1 has been idle, the first idletime t_(IDLE)_1 may have a value other than 0. If any one memory deviceof the second to eighth memory devices 100_2 to 100_8 is in operation,the idle time of the operating memory device may be determined to be 0.

At step S520, an idle time t_(IDLE) of memory devices including at leastone unselected memory device among the plurality of memory devices maybe determined. In this case, the idle time t_(IDLE) of memory devicesincluding the unselected memory device that is coupled to the samechannel as that of the selected memory device and to a way differentfrom that of the selected memory device may be determined. In FIG. 38,the unselected memory device that is coupled to the same channel CH1 asthat of the first memory device 100_1 and to a way WAY2 different fromthat WAY1 of the first memory device 100_1 may be the second memorydevice 100_2. At step S520, the idle time t_(IDLE) of the memory devicesincluding the second memory device 100_2 may be determined.

In an embodiment, the idle time t_(IDLE) at step S520 may be determinedto be the second idle time t_(IDLE)_2.

In an embodiment, the idle time t_(IDLE) at step S520 may be determinedto be the sum of the first idle time t_(IDLE)_1 and the second idle timet_(IDLE)_2. In an embodiment, the idle time t_(IDLE) at step S520 may bedetermined to be the sum of the second idle time t_(IDLE)_2 and any oneof the third to eighth idle times t_(IDLE)_3 to t_(IDLE)_8.

In an embodiment, the idle time t_(IDLE) at step S520 may be determinedto be the sum of the second idle time t_(IDLE)_2 and any two of thefirst and the third to eighth idle times t_(IDLE)_1 and t_(IDLE)_3 tot_(IDLE)_8.

In an embodiment, the idle time t_(IDLE) at step S520 may be determinedto be the sum of the second idle time t_(IDLE)_2 and any three of thefirst and the third to eighth idle times t_(IDLE)_1 and t_(IDLE)_3 tot_(IDLE)_8.

In an embodiment, the idle time t_(IDLE) at step S520 may be determinedto be the sum of the second idle time t_(IDLE)_2 and any four of thefirst and the third to eighth idle times t_(IDLE)_1 and t_(IDLE)_3 tot_(IDLE)_8.

In an embodiment, the idle time t_(IDLE) at step S520 may be determinedto be the sum of the second idle time t_(IDLE)_2 and any five of thefirst and the third to eighth idle times t_(IDLE)_1 and t_(IDLE)_3 tot_(IDLE)_8.

In an embodiment, the idle time t_(IDLE) at step S520 may be determinedto be the sum of the second idle time t_(IDLE)_2 and any six of thefirst and the third to eighth idle times t_(IDLE)_1 and t_(IDLE)_3 tot_(IDLE)_8.

In an embodiment, the idle time t_(IDLE) at step S520 may be determinedto be the sum of all of the first to eighth idle times t_(IDLE)_1 tot_(IDLE)_8.

FIG. 39 is a diagram illustrating a memory controller suitable for useas the memory controller 200 shown in FIG. 1 according to an embodiment.

Referring to FIG. 39, a memory controller 1000 is connected to a hostand a memory device. The memory controller 1000 is configured to accessthe memory device in response to a request received from the host. Forexample, the memory controller 1000 is configured to control read,program, erase, and background operations of the memory device. Thememory controller 1000 is configured to provide an interface between thememory device and the host. The memory controller 1000 is configured todrive firmware for controlling the memory device.

The memory controller 1000 may include a processor 1010, a memory buffer1020, an error correction code (ECC) circuit 1030, a host interface1040, a buffer control circuit 1050, a memory interface 1060, and a bus1070.

The bus 1070 may be configured to provide channels between components ofthe memory controller 1000.

The processor 1010 may control overall operations of the memorycontroller 1000, and perform a logical operation. The processor 1010 maycommunicate with the external host through the host interface 1040, andcommunicate with the memory device through the memory interface 1060.Also, the processor 1010 may communicate with the memory buffer 1020through the buffer control circuit 1050. The processor 1010 may controlan operation of the storage device, using the memory buffer 1020 as aworking memory, a cache memory or a buffer memory.

The processor 1010 may perform a function of a flash translation layer(FTL). The processor 1010 may translate a logical block address (LBA)provided by the host through the FTL into a physical block address(PBA). The FTL may receive an LBA, and translate it into a PBA using amapping table. Several address mapping methods of the FTL existaccording to mapping units. A representative address mapping methodincludes a page mapping method, a block mapping method, and a hybridmapping method.

The processor 1010 is configured to randomize data received from thehost. For example, the processor 1010 may randomize data received fromthe host, using a randomizing seed. The randomized data is provided asdata to be stored to the memory device to be programmed in the memorycell array.

The processor 1010 may perform randomizing and derandomizing by drivingsoftware or firmware.

In an embodiment, the processor 1010 may record a foggy programcompletion time by receiving a foggy program completion responsecorresponding to a foggy program command from the memory device (100shown in FIG. 2), and output a fine program command to the memory device(100 shown in FIG. 2) according to whether a time elapsed from the foggyprogram completion time has exceeded a reference time.

Before the processor 1010 outputs the fine program command, theprocessor 1010 may output a dummy program command to the memory device(100 shown in FIG. 2) according to whether a page on which a fineprogram operation is performed is influenced by interference.

The memory buffer 1020 may be used as the working memory, the cachememory, or the buffer memory of the processor 1010. The memory buffer1020 may store codes and commands, which are executed by the processor1010. The memory buffer 1020 may include a Static RAM (SRAM) or aDynamic RAM (DRAM).

The ECC circuit 1030 may perform an ECC operation. The ECC circuit 1030may perform ECC encoding on data to be written in the memory devicethrough the memory interface 1060. The ECC encoded data may betransferred to the memory device through the memory interface 1060. TheECC circuit 1030 may perform ECC decoding on data received from thememory device through the memory interface 1060. In an example, the ECCcircuit 1030 may be included as a component of the memory interface 1060in the memory interface 1060.

The host interface 1040 may communicate with the external host under thecontrol of the processor 1010. The host interface 1040 may communicatewith the host, using at least one of various communication manners, suchas a Universal Serial bus (USB), a Serial AT Attachment (SATA), a HighSpeed InterChip (HSIC), a Small Computer System Interface (SCSI),Firewire, a Peripheral Component Interconnection (PCI), a PCI express(PCIe), a nonvolatile memory express (NVMe), a Universal Flash Storage(UFS), a Secure Digital (SD) card, a Multi-Media Card (MMC), an embeddedMMC (eMMC), a Dual In-line Memory Module (DIMM), a Registered DIMM(RDIMM), and/or a Load Reduced DIMM (LRDIMM).

The buffer control circuit 1050 is configured to control the memorybuffer 1020 under the control of the processor 1010.

The memory interface 1060 is configured to communicate with the memorydevice under the control of the processor 1010. The memory interface1060 may communicate a command, an address, and data with the memorydevice through a channel.

When the memory device included in the storage device (50 of FIG. 1)starts an operation, the processor 1010 may control an initial operationfrequency based on the idle time of the corresponding memory device. Inan embodiment, the processor 1010 may monitor the idle time of thememory device included in the storage device (50 of FIG. 1) and updatethe monitored idle time t0 the memory buffer 1020. When the memorydevice that has been idle starts the operation, the processor 1010 maydetermine the initial operation frequency based on the idle time storedin the memory buffer 1020. The memory interface 1060 may generate aclock signal to be transmitted to the memory device, based on theinitial operation frequency determined by the processor 1010.

Therefore, the idle time monitor 260 of FIG. 25 may be implemented asthe processor 1010 and the memory buffer 1020 of FIG. 39. The clocksignal generator 270 of FIG. 25 may be implemented as the memoryinterface 1060 of FIG. 39.

In an example, the memory controller 1000 may not include the memorybuffer 1020 and the buffer control circuit 1050. Either or both of thesecomponents may be provided separately, or either or both of theirfunctions may be distributed among other components of the memorycontroller 1000.

In an example, the processor 1010 may control an operation of the memorycontroller 1000 by using codes. The processor 1010 may load codes from anonvolatile memory device (e.g., a read only memory (ROM)) provided inthe memory controller 1000. In another example, the processor 1010 mayload codes from the memory device through the memory interface 1060.

In an example, the bus 1070 of the memory controller 1000 may be dividedinto a control bus and a data bus. The data bus may transmit data in thememory controller 1000, and the control bus may transmit controlinformation such as a command and an address in the memory controller1000. The data bus and the control bus are separated from each other, sothat neither interferes with nor influences the other. The data bus maybe connected to the host interface 1040, the buffer control circuit1050, the ECC circuit 1030, and the memory interface 1060. The controlbus may be connected to the host interface 1040, the processor 1010, thebuffer control circuit 1050, the memory buffer 1020, and the memoryinterface 1060.

FIG. 40 is a block diagram illustrating a Solid State Drive (SSD) systemto which the storage device is applied in accordance with an embodimentof the present disclosure.

Referring to FIG. 40, the SSD system 3000 includes a host 3100 and anSSD 3200. The SSD 3200 exchanges a signal SIG with the host 3100 througha signal connector 3001, and receives power PWR through a powerconnector 3002. The SSD 3200 includes an SSD controller 3210, aplurality of flash memories 3221 to 322 n, an auxiliary power supply3230, and a buffer memory 3240.

In an embodiment, the SSD controller 3210 may serve as the memorycontroller 200 described with reference to FIG. 1.

The SSD controller 3210 may control the plurality of flash memories 3221to 322 n in response to a signal SIG received from the host 3100. In anexample, the signal SIG may be based on an interface between the host3100 and the SSD 3200. For example, the signal SIG may be defined by atleast one of interfaces such as a Universal Serial Bus (USB), aMulti-Media Card (MMC), an embedded MMC (eMMC), a Peripheral ComponentInterconnection (PCI), a PCI express (PCIe), an Advanced TechnologyAttachment (ATA), a Serial-ATA (SATA), a Parallel-ATA (PATA), a SmallComputer System Interface (SCSI), an Enhanced Small Disk Interface(ESDI), an Integrated Drive Electronics (IDE), a firewire, a UniversalFlash Storage (UFS), a WI-FI, a Bluetooth, and/or an NVMe.

In an embodiment, when the plurality of flash memories 3221 to 322 nsimultaneously start or end operations, the SSD controller 3210 mayapply or interrupt a dummy pulse to or from first to nth channels CH1 toCHn through which the SSD controller 3210 is coupled to the plurality offlash memories 3221 to 322 n.

In an embodiment, before the plurality of flash memories 3221 to 322 nsimultaneously start operations, the SSD controller 3210 maysequentially apply a dummy pulse to the first to nth channels CH1 toCHn. After the dummy pulse is applied to the first to nth channels CH1to CHn, the plurality of flash memories 3221 to 322 n may simultaneouslystart the operations.

In addition, when the plurality of flash memories 3221 to 322 nsimultaneously end operations, the SSD controller 3210 may apply a dummypulse to the first to nth channels CH1 to CHn after the plurality offlash memories 3221 to 322 n end the operations, and sequentiallyinterrupt the dummy pulses applied to the first to nth channels CH1 toCHn.

In an embodiment, when any one of the plurality of flash memories 3221to 322 n starts an operation, the SSD controller 3210 may control aninitial frequency of an output clock signal based on an idle timet_(IDLE) of the corresponding flash memory. In the case where the idletime t_(IDLE) of the corresponding flash memory exceeds the thresholdtime t_(THR), the SSD controller 3210 may generate a clock signal basedon an initial frequency FR_(IS) less than the normal frequency FR_(NM)during an initial frequency scaling period. If the initial frequencyscaling period has passed and the process enters a normal operationperiod, the SSD controller 3210 may generate a clock signal to be outputto the corresponding flash memory based on the normal frequency FR_(NM).Therefore, if the plurality of memory devices 3221 to 322 n startoperations at the same time, the entire current consumption of the SSDsystem 3000 may be prevented from rapidly increasing by reducing theinitial operation frequency.

The auxiliary power supply 3230 is connected to the host 3100 throughthe power connector 3002. When the supply of power from the host 3100 isnot smooth, the auxiliary power supply 3230 may provide power to the SSD3200. In an example, the auxiliary power supply 3230 may be located inthe SSD 3200, or be disposed externally to the SSD 3200. For example,the auxiliary power supply 3230 may be located on a main board, andprovide auxiliary power to the SSD 3200.

The buffer memory 3240 operates as a buffer memory of the SSD 3200. Forexample, the buffer memory 3240 may temporarily store data received fromthe host 3100 or data received from the plurality of flash memories 3221to 322 n, or temporarily store meta data (e.g., a mapping table) of theflash memories 3221 to 322 n. The buffer memory 3240 may include any ofvarious types of volatile memories such as a DRAM, an SDRAM, a DDRSDRAM, an LPDDR SDRAM, and/or a GRAM or any of various types ofnonvolatile memories such as a FRAM, a ReRAM, an STT-MRAM, and/or aPRAM.

FIG. 41 is a block diagram illustrating a user system to which thestorage device is applied in accordance with an embodiment of thepresent disclosure.

Referring to FIG. 41, the user system 4000 includes an applicationprocessor 4100, a memory module 4200, a network module 4300, a storagemodule 4400, and a user interface 4500.

The application processor 4100 may drive components included in the usersystem 4000, an operating system (OS), a user program, or the like. Inan example, the application processor 4100 may include controllers forcontrolling components included in the user system 4000, interfaces, agraphic engine, and the like. The application processor 4100 may beprovided as a System-on-Chip (SoC).

In an embodiment, when a plurality of memory devices included in thestorage module 4400 simultaneously start or end operations, theapplication processor 4100 may apply or interrupt a dummy pulse to orfrom channels through which the application processor 4400 is coupled,to the plurality of memory devices.

In an embodiment, before the plurality of memory devices included in thestorage module 4400 simultaneously start operations, the applicationprocessor 4100 may sequentially apply a dummy pulse to the channels.After the dummy pulse is applied to all the channels, the plurality ofmemory devices in the storage module 4400 may simultaneously start theoperations.

In addition, when the plurality of memory devices in the storage module4400 simultaneously end operations, the application processor 4100 mayapply a dummy pulse to the channels after the plurality of memorydevices end the operations, and sequentially interrupt the dummy pulsesapplied to the channels.

In an embodiment, when any one of a plurality of memory devices includedin the storage module 4400 starts an operation, the applicationprocessor 4100 may control an initial frequency of a clock signal to beoutput to a channel the application processor 4100 and the correspondingmemory device, based on an idle time t_(IDLE) of the correspondingmemory device. In the case where the idle time t_(IDLE) of thecorresponding memory device exceeds the threshold time t_(THR), theapplication processor 4100 may output a generated clock signal to thechannel between the application processor 4100 and the correspondingmemory device, based on an initial frequency FR_(IS) less than thenormal frequency FR_(NM) during an initial frequency scaling period. Ifthe initial frequency scaling period has passed and the process enters anormal operation period, the application processor 4100 may output agenerated clock signal to the channel between the application processor4100 and the corresponding memory device based on the normal frequencyFR_(NM). Therefore, if the plurality of memory devices included in thestorage module 4400 start operations at the same time, the entirecurrent consumption of the user system 4000 may be prevented fromrapidly increasing by reducing the initial operation frequency.

The memory module 4200 may operate as a main memory, working memory,buffer memory or cache memory of the user system 4000. The memory module4200 may include any of various types of volatile random access memoriessuch as a DRAM, an SDRAM, a DDR SDRAM, a DDR2 SDRAM, a DDR3 SDRAM, anLPDDR SDRAM, an LPDDR2 SDRAM, and/or an LPDDR3 SDRAM or any of varioustypes of nonvolatile random access memories such as a PRAM, a ReRAM, anMRAM, and/or a FRAM. In an example, the application processor 4100 andthe memory module 4200 may be provided as one semiconductor package bybeing packaged based on a Package on Package (PoP).

The network module 4300 may communicate with external devices. In anexample, the network module 4300 may support wireless communicationssuch as Code Division Multiple Access (CDMA), Global System for Mobilecommunication (GSM), Wideband CDMA (WCDMA), CDMA-2000, Time DivisionMultiple Access (TDMA), Long Term Evolution (LTE), Wimax, WLAN, UWB,Bluetooth, and Wi-Fi. In an example, the network module 4300 may beincluded in the application processor 4100.

The storage module 4400 may store data. For example, the storage module4400 may store data received from the application processor 4100.Alternatively, the storage module 4400 may transmit data stored thereinto the application processor 4100. In an example, the storage module4400 may be implemented with a nonvolatile semiconductor memory devicesuch as a Phase-change RAM (PRAM), a Magnetic RAM (MRAM), a ResistiveRAM (RRAM), a NAND flash, a NOR flash, or a NAND flash having athree-dimensional structure. In an example, the storage module 4400 maybe provided as a removable drive such as a memory card of the usersystem 4000 or an external drive.

In an example, the storage module 4400 may include a plurality ofnonvolatile memory devices, each of which may operate the same as thememory device described with reference to FIGS. 3 and 4. The storagemodule 4400 may operate the same as the storage device 50 described withreference to FIG. 2.

The user interface 4500 may include interfaces for inputting data orcommands to the application processor 4100 or outputting data to anexternal device. In an example, the user interface 4500 may include userinput interfaces such as a keyboard, a keypad, a button, a touch panel,a touch screen, a touch pad, a touch ball, a camera, a microphone, agyroscope sensor, a vibration sensor and a piezoelectric element. Theuser interface 4500 may include user output interfaces such as a LiquidCrystal Display (LCD), an Organic Light Emitting Diode (OLED) displaydevice, an Active Matrix OLED (AMOLED) display device, an LED, aspeaker, and a monitor.

In accordance with embodiments of the present disclosure, a number ofchannels coupled to memory devices to start operations is determinedbased on a request received from the host, total current is sequentiallyincreased based on the determined number of channels, a number ofchannels coupled to memory devices to end operations is determined basedon a chip enable signal and a command queue, and current may besequentially decreased based on the determined number of channels.

FIG. 42 is a block diagram illustrating a data processing system 10including a memory system 20 in accordance with an embodiment of thepresent disclosure.

Referring to FIG. 42, the data processing system 10 may include a host300 operably coupled with a memory system 20. In an embodiment, the host300, a controller 200, and a memory device 100 shown in FIG. 42 may besuitable for use as the host 300, the memory controller 200, and thememory device 100 shown in FIG. 1, respectively.

The host 300 may include any of a variety of portable electronicdevices, such as a mobile phone, an MP3 player, and a laptop computer,or an electronic device such as a desktop computer, a game player, atelevision (TV), a projector, and the like.

The host 300 also includes at least one operating system (OS), which cangenerally manage, and control functions and operations performed in thehost 300. The OS may provide interoperability between the host 300coupled with the memory system 20 and the user of the memory system 20.The OS may support functions and operations corresponding to user'srequests. By way of example but not limitation, the OS may include ageneral operating system and a mobile operating system according tomobility of the host 300. The general operating system may be split intoa personal operating system and an enterprise operating system accordingto system requirements or user's environment. The personal operatingsystem, including Windows and Chrome, may be subject to support servicesfor general purposes. The enterprise operating systems may bespecialized for securing and supporting high performance, includingWindows servers, Linux, and Unix. Further, the mobile operating systemmay include an Android and iOS. The mobile operating system may besubject to support services or functions for mobility (e.g., a powersaving function). The host 300 may include a plurality of operatingsystems. The host 300 may execute multiple operating systems incooperation with the memory system 20, corresponding to a user'srequest. The host 300 may transmit a plurality of commands correspondingto the user's requests to the memory system 20, thereby performingoperations corresponding to commands within the memory system 20.Handling plural commands in the memory system 20 will be described belowwith reference to FIGS. 45 and 46.

The memory system 20 may perform a specific function or operation inresponse to a request from the host 300 and, particularly, may storedata to be accessed by the host 300. The memory system 20 may be used asa main memory system or an auxiliary memory system of the host 300. Thememory system 20 may be implemented with any one of various types ofstorage devices, which may be electrically coupled with the host 300,according to a protocol of a host interface. Non-limiting examples ofsuitable storage devices include a solid state drive (SSD), a multimediacard (MMC), an embedded MMC (eMMC), a reduced size MMC (RS-MMC), amicro-MMC, a secure digital (SD) card, a mini-SD, a micro-SD, auniversal serial bus (USB) storage device, a universal flash storage(UFS) device, a compact flash (CF) card, a smart media (SM) card, and amemory stick.

The storage devices for the memory system 20 may be implemented with avolatile memory device, for example, a dynamic random access memory(DRAM) or a static RAM (SRAM), and/or a nonvolatile memory device suchas a read only memory (ROM), a mask ROM (MROM), a programmable ROM(PROM), an erasable programmable ROM (EPROM), an electrically erasableprogrammable ROM (EEPROM), a ferroelectric RAM (FRAM), a phase-changeRAM (PRAM), a magneto-resistive RAM (MRAM), a resistive RAM (RRAM orReRAM), or a flash memory.

The memory system 20 may include a controller (or a memory controller)200 and a memory device 100. The memory device 100 may store data to beaccessed by the host 300. The controller 200 may control storage of datain the memory device 100.

The controller 200 and the memory device 100 may be integrated into asingle semiconductor device, which may be included in any of the varioustypes of memory systems as described above.

By way of example but not limitation, the controller 200 and the memorydevice 100 may be integrated into a single semiconductor device. Thecontroller 200 and memory device 100 may be integrated to form an SSDwith improved operation speed. When the memory system 20 is used as anSSD, the operating speed of a host 300 connected to the memory system 20can be faster than that of a host 300 connected with a hard disk. Inanother embodiment, the controller 200 and the memory device 100 may beintegrated into one semiconductor device to form a memory card, such asa PC card (PCMCIA), a compact flash card (CF), a smart media card (e.g.,SM, SMC), a memory stick, a multimedia card (e.g., MMC, RS-MMC,MMCmicro), a secure digital (SD) card (e.g., SD, miniSD, microSD, SDHC),or a universal flash memory.

The memory system 20 may be configured as a part of, for example, acomputer, an ultra-mobile PC (UMPC), a workstation, a net-book, apersonal digital assistant (PDA), a portable computer, a web tablet, atablet computer, a wireless phone, a mobile phone, a smart phone, ane-book, a portable multimedia player (PMP), a portable game player, anavigation system, a black box, a digital camera, a digital multimediabroadcasting (DMB) player, a 3-dimensional (3D) television, a smarttelevision, a digital audio recorder, a digital audio player, a digitalpicture recorder, a digital picture player, a digital video recorder, adigital video player, a storage configuring a data center, a devicecapable of transmitting and receiving information under a wirelessenvironment, one of various electronic devices configuring a homenetwork, one of various electronic devices configuring a computernetwork, one of various electronic devices configuring a telematicsnetwork, a radio frequency identification (RFID) device, or one ofvarious components configuring a computing system.

The memory device 100 may be a nonvolatile memory device and may retaindata stored therein even while electrical power is not supplied. Thememory device 100 may store data provided from the host 300 through awrite operation, while providing data stored therein to the host 300through a read operation. The memory device 100 may include a pluralityof memory blocks 152, 154, and 156, each of which may include aplurality of pages. Each of the plurality of pages may include aplurality of memory cells to which a plurality of word lines (WL) areelectrically coupled. The memory device 100 also includes a plurality ofmemory dies, each of which includes a plurality of planes, each of whichincludes memory blocks, among the plurality of memory blocks 152, 154,and 156. In addition, the memory device 100 may be a non-volatile memorydevice, for example a flash memory, and the flash memory may have athree-dimensional stack structure.

The controller 200 may control overall operations of the memory device100, such as read, write, program and erase operations. For example, thecontroller 200 may control the memory device 100 in response to arequest from the host 300. The controller 200 may provide data read fromthe memory device 100 to the host 300. The controller 200 may store dataprovided by the host 300 in the memory device 100.

The controller 200 may include a host interface (I/F) 132, a processor134, error correction code (ECC) unit 138, a power management unit (PMU)140, a memory interface (I/F) 142, and a memory 144, all operativelycoupled via an internal bus.

The host interface 132 may process commands and data provided from thehost 300, and may communicate with the host 300 through at least one ofvarious interface protocols, such as universal serial bus (USB),multimedia card (MMC), peripheral component interconnect-express (PCI-eor PCIe), small computer system interface (SCSI), serial-attached SCSI(SAS), serial advanced technology attachment (SATA), parallel advancedtechnology attachment (PATA), small computer system interface (SCSI),enhanced small disk interface (ESDI) and integrated drive electronics(IDE). In accordance with an embodiment, the host interface 132 is acomponent for exchanging data with the host 300, which may beimplemented through firmware called a host interface layer (HIL).

The ECC unit 138 may correct error bits of the data to be processed in(e.g., outputted from) the memory device 100, which may include an ECCencoder and an ECC decoder. Here, the ECC encoder may perform errorcorrection encoding of data to be programmed in the memory device 100 togenerate encoded data into which a parity bit is added and store theencoded data in memory device 100. The ECC decoder may detect andcorrect errors contained in data read from the memory device 100 whenthe controller 200 reads the data stored in the memory device 100. Inother words, after performing error correction decoding on the data readfrom the memory device 100, the ECC unit 138 may determine whether theerror correction decoding has succeeded and output an instruction signal(e.g., a correction success signal or a correction fail signal). The ECCunit 138 may use the parity bit which is generated during the ECCencoding process, for correcting the error bit of the read data. Whenthe number of error bits is greater than or equal to a threshold numberof correctable error bits, the ECC unit 138 may not correct error bitsbut instead may output an error correction fail signal indicatingfailure in correcting the error bits.

The ECC unit 138 may perform an error correction operation based on acoded modulation such as a low density parity check (LDPC) code, aBose-Chaudhuri-Hocquenghem (BCH) code, a turbo code, a Reed-Solomon (RS)code, a convolution code, a recursive systematic code (RSC), atrellis-coded modulation (TCM), or a Block coded modulation (BCM). TheECC unit 138 may include any and all circuits, modules, systems ordevices for performing the error correction operation based on at leastone of the above described codes.

The PMU 140 may manage electrical power in the controller 200. Forexample, the PMU 140 may detect power-on and power-off. In addition, thePMU 140 may include a power detector.

The memory interface 142 may serve as an interface for handling commandsand data transferred between the controller 200 and the memory device100, to allow the controller 200 to control the memory device 100 inresponse to a request delivered from the host 300. The memory interface142 may generate a control signal for the memory device 100 and mayprocess data entered into or outputted from the memory device 100 underthe control of the processor 134 in a case when the memory device 100 isa flash memory and, in particular, when the memory device 100 is a NANDflash memory. The memory interface 142 may provide an interface forhandling commands and data between the controller 200 and the memorydevice 100, for example, to perform operations of NAND flash interface,in particular, operations between the controller 200 and the memorydevice 100. In accordance with an embodiment, the memory interface 142may be implemented through firmware called a flash interface layer (FIL)as a component for exchanging data with the memory device 100.

The memory 144 may support operations performed by the memory system 20and the controller 200. The memory 144 may store temporary ortransactional data generated or delivered for operations in the memorysystem 20 and the controller 200. The controller 200 may control thememory device 100 in response to a request from the host 300. Thecontroller 200 may deliver data read from the memory device 100 into thehost 300. The controller 200 may store data entered through the host 300within the memory device 100. The memory 144 may store data used by thecontroller 200 and the memory device 100 to perform operations such asread operations or program/write operations.

The memory 144 may be a volatile memory. The memory 144 may beimplemented with a static random access memory (SRAM), a dynamic randomaccess memory (DRAM), or both. Although FIG. 42 shows the memory 144disposed within the controller 200, embodiments are not limited to thatarrangement. That is, the memory 144 may be within or external to thecontroller 200. For instance, the memory 144 may be an external volatilememory having a memory interface transferring data and/or signalsbetween the memory 144 and the controller 200.

The memory 144 may store data for performing operations such as datawriting and data reading requested by the host 300 and/or data transferbetween the memory device 100 and the controller 200 for backgroundoperations such as garbage collection and wear levelling. In accordancewith an embodiment, for supporting operations in the memory system 20,the memory 144 may include a program memory, a data memory, a writebuffer/cache, a read buffer/cache, a data buffer/cache, and a mapbuffer/cache.

The processor 134 may be a microprocessor or a central processing unit(CPU). The memory system 20 may include one or more processors 134. Theprocessor 134 may control the overall operations of the memory system20. By way of example but not limitation, the processor 134 can controla program operation or a read operation of the memory device 100, inresponse to a write request or a read request entered from the host 300.In accordance with an embodiment, the processor 134 may use or executefirmware to control the overall operations of the memory system 20.Herein, the firmware may be a flash translation layer (FTL). The FTL mayserve as an interface between the host 300 and the memory device 100.The host 300 may transmit requests for write and read operations to thememory device 100 through the FTL.

The FTL may manage operations of address mapping, garbage collection,wear-leveling and so forth. Particularly, the FTL may load, generate,update, or store map data. Therefore, the controller 200 may map alogical address, which is entered from the host 300, with a physicaladdress of the memory device 100 through the map data. The memory device100 may function as a general storage device to perform a read or writeoperation. Also, through the address mapping operation based on the mapdata, when the controller 200 tries to update data stored in aparticular page, the controller 200 may program the updated data onanother empty page and may invalidate old data of the particular page(e.g., update a physical address, corresponding to a logical address ofthe updated data, from the particular page to the newly programed page)due to a characteristic of a flash memory device. Further, thecontroller 200 may store map data of the new data into the FTL.

For example, when performing an operation requested from the host 300 inthe memory device 100, the controller 200 uses the processor 134. Theprocessor 134 engaged with the memory device 100 may handle instructionsor commands corresponding to an inputted command from the host 300. Thecontroller 200 may perform a foreground operation as a commandoperation, corresponding to a command from the host 300, such as aprogram operation corresponding to a write command, a read operationcorresponding to a read command, an erase/discard operationcorresponding to an erase/discard command, and a parameter set operationcorresponding to a set parameter command or a set feature command with aset command.

The controller 200 may perform a background operation on the memorydevice 100 through the processor 134. By way of example but notlimitation, the background operation for the memory device 100 includescopying data in a memory block, among the memory blocks 152, 154, and156, and storing such data in another memory block, for example, agarbage collection (GC) operation. The background operation may includean operation to move data stored in at least one of the memory blocks152, 154, and 156 in the memory device 100, into at least another of thememory blocks 152, 154, and 156, for example, a wear leveling (WL)operation. During a background operation, the controller 200 may use theprocessor 134 for storing the map data stored in the controller 200 toat least one of the memory blocks 152, 154, and 156, for example, a mapflush operation. A bad block management operation of checking for badblocks among the plurality of memory blocks 152, 154, and 156 is anotherexample of a background operation performed by the processor 134.

In the memory system 20, the controller 200 performs a plurality ofcommand operations corresponding to a plurality of commands receivedfrom the host 300. For example, when performing a plurality of programoperations corresponding to plural program commands, a plurality of readoperations corresponding to plural read commands, and a plurality oferase operations corresponding to plural erase commands sequentially,randomly, or alternatively, the controller 200 may determine whichchannel(s) or way(s) for connecting the controller 200 to which memorydie(s) in the memory device 100 is/are proper or appropriate forperforming each operation. The controller 200 may transmit data orinstructions via the channel(s) or way(s) for performing each operation.The plurality of memory dies may transmit an operation result via thesame channel(s) or way(s), respectively, after each operation iscomplete. Then, the controller 200 may transmit a response or anacknowledge signal to the host 300. In an embodiment, the controller 200may check a status of each channel or each way. In response to a commandreceived from the host 300, the controller 200 may select at least onechannel or way based on the status of each channel or each way so thatinstructions and/or operation results with data may be delivered viaselected channel(s) or way(s).

The controller 200 may check the states of a plurality of channels (orways) coupled to a plurality of memory dies that are included in thememory device 100.

By way of example but not limitation, the controller 200 may recognizestatuses regarding channels (or ways) associated with memory dies in thememory device 100. The controller 200 may determine each channel or eachway as being in a busy state, a ready state, an active state, an idlestate, a normal state, or an abnormal state. The controller'sdetermination of which channel or way an instruction (and/or data) isdelivered through can be based on a physical block address, e.g., towhich die(s) the instruction (and/or the data) is delivered. Thecontroller 200 may refer to descriptors delivered from the memory device100. The descriptors may include a block or page of parameters thatdescribe characteristics of the memory device 100, and may have a setformat or structure. The descriptors may include device descriptors,configuration descriptors, unit descriptors, and the like. Thecontroller 200 can refer to, or use, the descriptors to determine withwhich channel(s) or way(s) an instruction or a data is exchanged.

A management unit (not shown) may be included in the processor 134. Themanagement unit may perform bad block management of the memory device100. The management unit may find bad memory blocks, which are inunsatisfactory condition for further use, as well as perform bad blockmanagement on the bad memory blocks. When the memory device 100 is aflash memory such as a NAND flash memory, a program failure may occurduring the write operation, for example, during the program operation,due to characteristics of a NAND logic function. During the bad blockmanagement, the data of the program-failed memory block or the badmemory block may be programmed into a new memory block. The bad blocksmay substantially reduce the utilization efficiency of the memory device100 having a 3D stack structure and the reliability of the memory system20. Thus, reliable bad block management may enhance or improveperformance of the memory system 20.

FIG. 43 is a block diagram illustrating an operation of a memory system20 in accordance with an embodiment of the present disclosure.

Referring to FIG. 43, the memory system 20 may include a controller 200and a memory device 100. The controller 200 may include a clockgenerator 1301, an input circuit 1302, and an internal circuit 1303. Thememory device 100 may include a loop-back operation circuit 1501, amemory cell region 1502, and an output circuit 1503. The clock generator1301 and the input circuit 1302 that are included in the controller 200may be constituent elements corresponding to the memory interface unit142 described as the constituent elements included in the controller 200shown in FIG. 42. Also, the internal circuit 1303 included in thecontroller 200 may be a constituent element corresponding to one or moreof the host interface unit 132, the processor 134, the error correctioncode (ECC) unit 138, the power management unit (PMU) 140, and the memory144, which are described as the constituent elements included in thecontroller 200 in FIG. 42. The memory cell region 1502 included in thememory device 100 may be a constituent element corresponding to thememory blocks 152, 154, and 156 that are described in FIG. 42 to beincluded in the memory device 150. Also, it is illustrated in thedrawing that one memory device 100 is included in the memory system 20.This is merely an example, and the memory system 20 may also includemore than one memory devices.

To be specific, the memory device 100 may include a memory cell region1502 for storing data, and the memory device 100 may loop back anexternal first source clock SCCLK1 to output a second source clockSCCLK2. Herein, the memory device 100 may synchronize read data RDDATA,which is read from the memory cell region 1502, with the second sourceclock SCCLK2 and output the resultant read data.

To be more specific, the memory device 100 may read the read data RDDATAfrom the memory cell region 1502 in response to a read command (notshown) inputted from the controller 130. Also, the memory device 100 maysynchronize the read data RDDATA with the second source clock SCCLK2which is obtained by looping back the first source clock SCCLK1 inputtedfrom the controller 200 and output the synchronized read data. In otherwords, the loop-back operation circuit 1501 included in the memorydevice 100 may output the second source clock SCCLK2, which is obtainedby looping back the first source clock SCCLK1 inputted from thecontroller 200, to the controller 200. Also, the output circuit 1503included in the memory device 100 may output the read data RDDATA thatis read from the memory cell region 1502 to the controller 200 insynchronization with the second source clock SCCLK2.

Herein, loop-back may refer to routing an input signal, digital datastreams, or flows of items without intentional processing ormodification.

The controller 200 may generate the first source clock SCCLK1, outputthe first source clock SCCLK1 to the memory device 100, and then receivethe read data RDDATA which is transferred from the memory device 100 inresponse to the second source clock SCCLK2 which is transferred from thememory device 100.

To be more specific, the clock generator 1301 included in the controller200 may generate the first source clock SCCLK1 and output the generatedfirst source clock SCCLK1 to the memory device 150. The input circuit1302 included in the controller 200 may receive the read data RDDATAwhich is transferred from the memory device 100 in response to thesecond source clock SCCLK2 which is transferred from the memory device100. The internal circuit 1303 included in the controller 200 may usethe read data RDDATA inputted through the input circuit 1302 accordingto a predetermined purpose. For example, the internal circuit 1303 mayperform an operation of outputting the read data RDDATA to the host 300in FIG. 42 in response to the host interface unit 132 in FIG. 42 and theprocessor 134 in FIG. 42.

Meanwhile, the size of the read data RDDATA requested by the controller200 to the memory device 100 through one read command may have apredetermined size. For example, the predetermined size for the readdata RDDATA may be approximately 2 KB. Herein, the predetermined sizefor the read data RDDATA may vary depending on the type of the memorydevice 100 or the selection of a designer.

Also, in order for the controller 200 to request the memory device 100for data having a larger or smaller size than the predetermined size forthe read data RDDATA, an additional operation may be required as shownin the following example.

For example, when the predetermined size for the read data RDDATA isapproximately 2 KB and data of a size of approximately 10 KB which islarger than the predetermined size are to be read from the memory device100, the controller 200 may transfer five read commands to the memorydevice 100 and then receive five read data RDDATAs each having a size ofapproximately 2 KB from the memory device 100.

Also, when the predetermined size for the read data RDDATA isapproximately 2 KB and data of a size of approximately 512 bytes, whichis smaller than the predetermined size, is to be read from the memorydevice 100, selection information for selecting data of approximately512 bytes from the read data RDDATA of 2 KB corresponding to a singleread command may be included in the single read command that istransferred to the memory device 100. In other words, the controller 200may transfer the single read command including the selection informationto the memory device 100 and then receive read data RDDATA ofapproximately 512 bytes from the memory device 100.

Meanwhile, when the read data RDDATA are read from the memory cellregion 1502 included in the memory device 100, errors may occur in somebits. Also, the values of some bits may be lost or an error may occurwhile the read data RDDATA are outputted from the memory device 100 andtransferred to the controller 200. As described above, some bits of theread data RDDATA transferred from the memory device 100 to thecontroller 200 may not be in a normal state, that is, errors may occuror the values of some bits may be lost. In this case, the controller 200may control the memory device 100 to re-read the read data RDDATA fromthe memory cell region 1502 and output the read data RDDATA that arere-read.

Herein, since the read data RDDATA have a predetermined size, when it isdetermined that some abnormal bits are included in the read data RDDATAreceived from the memory device 100, the controller 200 may request thememory device 100 to read and transfer the read data RDDATA of thepredetermined size again.

When the read data RDDATA are read back from the memory device 100because some abnormal bits are included in the read data RDDATA, aportion of the read data RDDATA including the abnormal bits and having agiven size smaller than a predetermined size can be read again andtransferred to the controller 200. In this case, an operation ofre-reading the portion of the read data RDDATA and transferring theportion of the read data RDDATA to the controller 200 may be moreefficient than an operation of re-reading the entire read data RDDATA ofthe predetermined size and transferring the entire read data RDDATA tothe controller 200. In order to efficiently perform the operation, theoperation of selecting data of the given size including the abnormalbits from the read data RDDATA of the predetermined size and controllingthe memory device 100 to read the selected data may be required. Thismay be realized through the following embodiments of the presentinvention.

Herein, when it is determined that some abnormal bits are included inthe read data RDDATA received from the memory device 100, the controller200 may include an error correction code unit (e.g., the ECC unit 138 inFIG. 42) and perform a recovery operation of recovering the read dataRDDATA in an abnormal state into a normal state in the error correctioncode unit 138. For example, the ECC unit 138 may be included in theinternal circuit 1303. However, the recovery operation of the errorcorrection code unit 138 may require a relatively longer time than therepetitive read operation of re-reading the read data RDDATA from thememory device 100 and transferring the read data RDDATA to thecontroller 200. Therefore, when the read data RDDATA are still in theabnormal state even after the repetitive read operation of re-readingthe read data RDDATA from the memory device 100 and transferring theread data RDDATA to the controller 200 is performed a predeterminednumber of times that is set by the designer, the recovery operation maybe attempted through the error correction code unit 138.

FIG. 44 is a block diagram illustrating an operation of a memory system20 in accordance an embodiment of the present disclosure.

Referring to FIG. 44, the memory system 20 may include a controller 200and a memory device 100. Herein, the controller 200 may include a clockgenerator 1301, an input circuit 1302, an internal circuit 1303, amodulation circuit 1304, and a verification circuit 1305. The memorydevice 100 may include a loop-back operation circuit 1501, a memory cellregion 1502, and an output circuit 1503. Herein, the clock generator1301, the input circuit 1302, the modulation circuit 1304, and theverification circuit 1305 included in the controller 200 may beconstituent elements corresponding to the memory interface unit 142 thatare described in FIG. 42 as the constituent elements included in thecontroller 200. Also, the internal circuit 1303 included in thecontroller 200 may be a constituent element corresponding to one or moreof the host interface unit 132, the processor 134, the error correctioncode (ECC) unit 138, the power management unit (PMU) 140, and the memory144 that are described in FIG. 42 as the constituent elements includedin the controller 200. The memory cell region 1502 included in thememory device 100 may be a constituent element corresponding to aplurality of memory blocks 152, 154, and 156 that are described in FIG.42 as the constituent elements included in the memory device 100. Also,it is described in the drawing that one memory device 100 is included inthe memory system 20. However, embodiments of the present disclosure arenot limited thereto. For example, a plurality of memory devices may beincluded in the memory system 20.

To be specific, the memory device 100 may include a memory cell region1502 for storing data, and the memory device 100 may loop back anexternally inputted first modulation clock DCLK1 to output a secondmodulation clock DCLK2. In this case, the memory device 100 maysynchronize read data RDDATA that are read from the memory cell region1502 with the second modulation clock DCLK2 and output resultantsynchronized data.

To be more specific, the memory device 100 may read the read data RDDATAfrom the memory cell region 1502 in response to a read command (notshown) inputted from the controller 200. Also, the memory device 100 maysynchronize the read data RDDATA with the second modulation clock DCLK2that is obtained by looping back the first modulation clock DCLK1inputted from the controller 200 and output the resultant synchronizeddata. In other words, the loop-back operation circuit 1501 included inthe memory device 100 may obtain the second modulation clock DCLK2 bylooping back the first modulation clock DCLK1 inputted from thecontroller 200 and output the second modulation clock DCLK2 to thecontroller 200. Also, the output circuit 1503 included in the memorydevice 100 may output the read data RDDATA that are read from the memorycell region 1502 to the controller 200 in synchronization with thesecond modulation clock DCLK2.

Herein, the word ‘loop-back’ (or loopback) may refer to routing an inputsignal that is received, digital data streams, or flows of items withoutintentional processing or modification. In an embodiment, the loop-backoperation circuit 1501 may be implemented as a circuit that couples afirst channel receiving the first modulation clock DCLK1 and a secondchannel transmitting the second modulation clock DCLK2. For example, thecircuit may include a unity-gain buffer coupled between the firstchannel and the second channel.

The controller 200 may generate a first modulation clock DCLK1 which isdivided into N consecutive modulation sections by performing amodulation operation on the source clock SCCLK according to a specificscheme, output the generated first modulation clock DCLK1 to the memorydevice 100, and then receive the read data RDDATA transferred from thememory device 100 in response to the second modulation clock DCLK2transferred from the memory device 100. Herein, N may be a naturalnumber equal to or greater than 2. Also, the controller 200 may verifythe reliability of the read data RDDATA corresponding to the Nmodulation sections included in the second modulation clock DCLK2 foreach modulation section through a demodulation operation according to aspecific scheme.

Herein, the operation of verifying the reliability of the read dataRDDATA in the controller 200 may include an operation of verifyingwhether or not abnormal data are included in the read data RDDATAinputted through the input circuit 1302. In other words, the controller200 may detect each of the N modulation sections included in the secondmodulation clock DCLK2 by performing a demodulation operation on thesecond modulation clock DCLK2 according to a specific scheme, and verifywhether there is an abnormal section data or not among the N sectiondata (not shown) that are included in the read data RDDATA andrespectively corresponding to the N modulation sections in the secondmodulation clock DCLK2. For example, abnormal section data in the readdata RDDATA may include one or more abnormal bits.

To be more specific, the clock generator 1301 included in the controller200 may generate a source clock SCCLK. Also, the modulation circuit 1304included in the controller 200 may generate a first modulation clockDCLK1 including N modulation sections by performing a modulationoperation on the source clock SCCLK according to a specific scheme, andthen output the first modulation clock DCLK1 to the memory device 100.In an embodiment, the modulation circuit 1304 is implemented as acircuit including a frequency modulation circuit. For example, themodulation circuit 1304 may include a frequency modulator that receivesa DC input and generates the first modulation signal DCLK1 in responseto the DC input by varying a value of the DC input to generate the Nmodulation sections of the first modulation signal DCLK1 havingdifferent frequencies. The input circuit 1302 included in the controller200 may receive the read data RDDATA transferred from the memory device100 in response to the second modulation clock DCLK2 transferred fromthe memory device 100. Also, the verification circuit 1305 included inthe controller 200 may verify the reliability of the read data RDDATAcorresponding to the N modulation sections that are included in thesecond modulation clock DCLK2 for each modulation section by performinga demodulation operation on the second modulation clock DCLK2 which istransferred from the memory device 100 according to a specific scheme.

The internal circuit 1303 included in the controller 200 may perform anoperation for securing the reliability of the read data RDDATA inputtedthrough the input circuit 1302 based on the verification informationVRINFO outputted from the verification circuit 1305, and then use theread data RDDATA inputted through the input circuit 1302 according to apredetermined purpose.

Herein, the operation that may be performed in the internal circuit 1303to secure the reliability of the read data RDDATA inputted through theinput circuit 1302 may be an operation of requesting the memory device100 to selectively re-read and output only abnormal section data fromthe memory cell region 1502 among N section data included in the readdata RDDATA respectively corresponding to the N modulation sectionsincluded in the second modulation clock DCLK2. In short, when it isassumed that the read data RDDATA have a predetermined size, it may bean operation of requesting the memory device 100 to re-read only someabnormal section data among the N section data included in the read dataRDDATA.

For example, although not illustrated in detail in the drawing, theinternal circuit 1303 may generate a read command for selectivelyre-reading abnormal section data and transfer the generated read commandto the memory device 150. Subsequently, when the section data that arerequested to be re-read are transferred to the controller 200 and thereliability is verified by the verification circuit 1305, the internalcircuit 1303 may use the entire read data RDDATA including the re-readsection data for a predetermined purpose. For example, referring back toFIG. 42, the internal circuit 1303 may perform an operation foroutputting the read data RDDATA to the host 300 communicating with thehost interface unit 132 and the processor 134.

Meanwhile, FIGS. 44, 46, and 47 may be referred to in order to describea modulation operation and a demodulation operation based on a specificscheme.

First of all, referring to FIGS. 44 and 46, the modulation operation andthe demodulation operation based on the specific scheme may meanfrequency modulation and frequency demodulation, respectively. In otherwords, the modulation operation based on the specific scheme mayindicate a modulation operation using N different frequencies. Herein,it is assumed that N is a natural number equal to or greater than 2, andit is assumed in FIG. 46 that N is 4.

To be specific, for example, the source clock SCCLK generated by theclock generator 1301 of the controller 200 may have a substantiallyuniform frequency.

The modulation circuit 1304 included in the controller 200 may perform afrequency modulation operation of modulating the frequency of the sourceclock SCCLK to generate the first modulation clock DCLK1 that is dividedinto four modulation sections A, B, C, and D. Herein, the fourmodulation sections A, B, C, and D included in the first modulationclock DCLK1 may be detected according to their frequency differences.For example, the D section among the four modulation sections includedin the first modulation clock DCLK1 may have substantially the samefrequency as the source clock SCCLK, and the C section may have a lowerfrequency than the D section, and the B section may have a lowerfrequency than the C section, and the section A may have a lowerfrequency than the section B. That is, according to the embodiment shownin FIG. 46, frequencies may increase in the order of the A section, theB section, the C section, and the D section in the first modulationclock DCLK1. However, embodiments of the present disclosure are notlimited thereto. For example, frequencies may decrease in the order ofthe A section, the B section, the C section, and the D section in thefirst modulation clock DCLK1. In an embodiment, the first modulationclock DCLK1 may include an odd number of modulation sections, ratherthan an even number (e.g., 4 in FIG. 46) of modulation sections. In anembodiment, a plurality of modulation sections of the first modulationclock DCLK1 have respective frequencies that are spaced apart at regularintervals.

Since the loop-back operation circuit 1501 included in the memory device100 loops back the first modulation clock DCLK1 so as to produce thesecond modulation clock DCLK2 and outputs the second modulation clockDCLK2 to the controller 200, the second modulation clock DCLK2 may alsoinclude four modulation sections A, B, C, and D. Therefore, the fourmodulation sections A, B, C, and D included in the second modulationclock DCLK2 may also be detected according to their frequencydifferences.

The output circuit 1503 included in the memory device 100 maysynchronize the read data RDDATA read from the memory cell region 1502with each of the four modulation sections A, B, C, and D that areincluded in the second modulation clock DCLK2. Therefore, the value ofthe read data RDDATA may be determined based on each of the fourmodulation sections A, B, C, and D that are included in the secondmodulation clock DCLK2. For example, it may be assumed that the memorydevice 100 is a NAND flash memory and the read data RDDATA has a datasize corresponding to four pages. In this case, a first portion of theread data RDDATA read from the first page (not shown) of the memory cellregion 1502 included in the memory device 100 may be first section datathat are synchronized with the A section among the four modulationsections A, B, C and D that are included in the second modulation clockDCLK2. A second portion of the read data RDDATA read from the secondpage (not shown) may be second section data that are synchronized withthe B section. A third portion of the read data RDDATA read from thethird page (not shown) may be third section data that are synchronizedwith the C section. A fourth portion of the read data RDDATA read fromthe fourth page (not shown) may be fourth section data that aresynchronized with the D section.

To sum up, the read data RDDATA may include first to fourth sectiondata. Also, the first to fourth section data included in the read dataRDDATA may be respectively synchronized to the four modulation sectionsA, B, C, and D included in the second modulation clock DCLK2. Herein,since the four modulation sections A, B, C, and D included in the secondmodulation clock DCLK2 have different frequencies, the first to fourthsection data included in the read data RDDATA may be in a state thatthey are respectively synchronized with clocks of different frequencies.

The input circuit 1302 included in the controller 200 may receive theread data RDDATA transferred from the memory device 100 in response tothe second modulation clock DCLK2 which is transferred from the memorydevice 100.

The verification circuit 1305 included in the controller 200 may performa frequency demodulation operation on the second modulation clock DCLK2transferred from the memory device 100 to detect the four modulationsections A, B, C, and D included in the second modulation clock DCLK2.In other words, the verification circuit 1305 may detect a change infrequency by performing a frequency demodulation operation onto thesecond modulation clock DCLK2 so as to produce a detection result, andmay detect the four consecutive modulation sections A, B, C, and D thatare included in the second modulation clock DCLK2 based on the detectionresult. In an embodiment, the verification circuit 1305 may beimplemented as a circuit including a frequency demodulation circuitwhose transfer function is sensitive to frequency. For example, theverification circuit 1305 may include a frequency to voltage convertergenerating an output voltage that is proportional to a frequency of aninput signal. The verification circuit 1305 may detect the first tofourth section data included in the read data RDDATA through anoperation of detecting the four consecutive modulation sections A, B, C,and D that are included in the second modulation clock DCLK2 by eachsection. In other words, the verification circuit 1305 may determine afirst portion of the read data RDDATA corresponding to the A sectionamong the four consecutive modulation sections A, B, C, and D that areincluded in the second modulation clock DCLK2 as first section data,determine a second portion of the read data RDDATA corresponding to theB section as second section data, determine a third portion of the readdata RDDATA corresponding to the C section as third section data, anddetermine a fourth portion of the read data RDDATA corresponding to theD section as fourth section data.

Also, the verification circuit 1305 may verify the reliability of theread data RDDATA for each modulation section by detecting the first tofourth section data that are included in the read data RDDATA. In otherwords, the verification circuit 1305 may independently verify whethereach of the first to fourth section data that are included in the readdata RDDATA is in a normal state or not.

For example, some bits included in the second section data among thefirst to fourth section data that are included in the read data RDDATAmay be lost in the process of being transferred from the memory device100 to the controller 200.

Herein, the verification circuit 1305 may verify that some bits of thesecond section data are missing among the first to fourth section datathat are included in the read data RDDATA and the second section dataare not in a normal state. Of course, the verification circuit 1305 maybe able to verify that the remaining section data, which include thefirst, third, and fourth section data, are in a normal state. Theverification circuit 1305 may generate verification information VRINFO,which represents a verification result that the second section dataamong the first to fourth section data included in the read data RDDATAare not in a normal state while the remaining first, third, and fourthsection data are in a normal state and output the verificationinformation VRINFO to the internal circuit 1303.

Accordingly, the internal circuit 1303 may be informed that the secondsection data among the first to fourth section data included in the readdata RDDATA are not in a normal state in response to the verificationinformation VRINFO outputted from the verification circuit 1305. As aresult, the internal circuit 1303 may request the memory device 100 toselectively re-read and output only the second section data from thememory cell region 1502. For example, the internal circuit 1303 maygenerate a read command (not shown) for selectively re-reading only thesecond section data and transfer the read command to the memory device100.

Herein, the internal circuit 1303 may stop the frequency modulationoperation of the modulation circuit 1304 and the frequency demodulationoperation of the verification circuit 1305 from a first time when theinternal circuit 1303 requests the memory device 100 to perform are-read operation to a second time when the re-read operation ends.

To be specific, the internal circuit 1303 may generate an operationselection signal OPC having a first value when the internal circuit 1303requests the memory device 100 to re-read the second section data, andtransfer the generated operation selection signal OPC to the modulationcircuit 1304 and the verification circuit 1305. Herein, the modulationcircuit 1304 may stop performing a frequency modulation operation inresponse to the operation selection signal OPC having the first valuetransferred from the internal circuit 1303. Similarly, the verificationcircuit 1305 may stop performing a frequency demodulation operation inresponse to the operation selection signal OPC having the first valuetransferred from the internal circuit 1303.

Herein, since the modulation circuit 1304 stops a frequency modulationoperation, the source clock SCCLK generated by the clock generator 1301may be transferred to the memory device 100 through the modulationcircuit 1304. In this case, the loop-back operation circuit 1501included in the memory device 100 may loop back the source clock SCCLKtransferred from the controller 200 to transfer the result to the outputcircuit 1503 included in the controller 200 and the memory device 100.Accordingly, the output circuit 1503 may output the second section datathat are re-read from the memory cell region 1502 to the controller 200in synchronization with the source clock SCCLK.

Also, the input circuit 1302 included in the controller 200 may receivethe second section data that are re-read from the memory device 100 inresponse to the source clock SCCLK transferred from the memory device100.

The verification circuit 1305 included in the controller 200 may verifyagain whether the second section data that are re-read from the memorydevice 100 is in a normal state or not. In this case, the verificationcircuit 1305 may keep stopping the frequency demodulation operationsince the modulation circuit 1304 stops the frequency modulationoperation. Therefore, the verification circuit 1305 may verify whetherthe second section data transferred from the memory device 100 is in anormal state or not in response to the source clock SCCLK.

As a result of re-verifying the second section data transferred from thememory device 100 in the verification circuit 1305, when the secondsection data are in a normal state, verification information VRINFOindicating that the second section data are in a normal state may begenerated and outputted to the internal circuit 1303. Accordingly, theinternal circuit 1303 may combine the second section data that arere-read and verified to be in a normal state with the first, third, andfourth section data that are previously read and verified to be in anormal state, and thus it may be regarded that the read data RDDATA inwhich the first to fourth section data are all verified to be in anormal state are received. Therefore, the internal circuit 1303 may usethe read data RDDATA whose first to fourth section data are all verifiedto be in a normal state according to a predetermined purpose. Also, theinternal circuit 1303 may generate an operation selection signal OPChaving a second value when the read data RDDATA whose first to fourthsection data are all verified to be in a normal state are received, andtransfer the generated operation selection signal OPC to the modulationcircuit 1304 and the verification circuit 1305. Herein, the modulationcircuit 1304 may resume performing the frequency modulation operation inresponse to the operation selection signal OPC having the second valuetransferred from the internal circuit 1303. Similarly, the verificationcircuit 1305 may resume performing the frequency demodulation operationin response to the operation selection signal OPC having the secondvalue transferred from the internal circuit 1303.

When the verification circuit 1305 re-verifies the second section datatransferred from the memory device 100 and it turns out that the secondsection data are still in an abnormal state, verification informationVRINFO representing that the second section data are in an abnormalstate may be generated again and outputted to the internal circuit 1303.In this case, the internal circuit 1303 may attempt a repetitive readoperation of requesting the memory device 100 to selectively re-read andoutput the second section data or attempt a recovery operation ofrecovering the abnormal second section data into a normal state throughan error correction code unit (e.g., the error correction code unit 138in FIG. 42). Herein, which of the repetitive read operation and therecovery operation is to be performed in the internal circuit 1303 maybe predetermined according to a designer's selection.

Referring to FIGS. 44 and 47, the modulation operation and thedemodulation operation based on a specific scheme may mean phasemodulation and phase demodulation, respectively. In other words, themodulation operation based on a specific scheme may mean a modulationoperation using N different phases. Herein, it is assumed that N is anatural number equal to or greater than 2 and it is assumed in FIG. 47that N is 4.

To be specific, for example, it may be regarded that the phase of thesource clock SCCLK generated in the clock generator 1301 of thecontroller 200 has a reference phase.

The modulation circuit 1304 included in the controller 200 may perform aphase modulation operation of modulating the phase of the source clockSCCLK to generate a first modulation clock DCLK1 that is divided intofour modulation sections A, B, C, and D. In this case, the fourmodulation sections A, B, C, and D included in the first modulationclock DCLK1 may be divided according to phase differences. For example,the section A among the four modulation sections included in the firstmodulation clock DCLK1 may have a phase difference of P1 with respect tothe source clock SCCLK, the section B may have a phase difference of P2with respect to the source clock SCCLK, the C section may have a phasedifference of P3 with respect to the source clock SCCLK, and the sectionD may have a phase difference of P4 with respect to the source clockSCCLK. In an embodiment, the verification circuit 1305 may beimplemented as a circuit including a phase demodulation circuit. In anembodiment, P1, P2, P3, and P4 may be approximately 45 degrees, 135degrees, 225 degrees, and 315 degrees, respectively.

To sum up, the modulation operation and the demodulation operation basedon a specific scheme′ may represent frequency modulation and frequencydemodulation, respectively, as described earlier with reference to FIGS.44 and 46. Also, the modulation operation and the demodulation operationbased on a specific scheme may mean phase modulation and phasedemodulation, respectively, that are described with reference to FIGS.44 and 47. As described above, the modulation operation and thedemodulation operation based on a specific scheme may have a differenceas shown in FIGS. 46 and 47, but the controller 200 and the memorydevice 100 of FIG. 44 operate similarly in that the controller 200generates a modulation clock DCLK1 including N modulation sections byperforming a modulation operation onto the source clock SCCLK, receivesthe read data RDDATA in synchronization with the modulation clock DCLK2,and performs an operation of verifying the reliability of the read dataRDDATA corresponding to the N modulation sections that are included inthe modulation clock DCLK2 by performing a demodulation operation.Therefore, detailed descriptions on the operation of the controller 200and the memory device 100 of FIG. 44 based on the scheme of FIG. 47 thatare similar to those described above with reference to FIGS. 44 and 47may be omitted in the interest of brevity.

FIG. 45 is a block diagram illustrating an operation of a memory system20 in accordance with an embodiment of the present disclosure.

Referring to FIG. 45, the memory system 20 may include a controller 200and a memory device 100. Herein, the controller 200 may include a clockgenerator 1301, an input circuit 1302, an internal circuit 1303, and averification circuit 1305. The memory device 100 may include amodulation circuit 1504, a memory cell region 1502, and an outputcircuit 1503. Herein, the clock generator 1301, the input circuit 1302,and the verification circuit 1305 included in the controller 200 may beconstituent elements corresponding to the memory interface unit 142which is described as a constituent element included in the controller200 in FIG. 42. Also, the internal circuit 1303 included in thecontroller 200 may be a constituent element corresponding to one or moreamong the host interface unit 132, the processor 134, the errorcorrection code (ECC) unit 138, the power management unit (PMU) 140, andthe memory 144, which are described as the constituent elements includedin the controller 200 in FIG. 42. The memory cell region 1502 includedin the memory device 100 may be a constituent element corresponding to aplurality of memory blocks 152, 154, and 156 described as being includedin the memory device 100 in FIG. 42. Also, FIG. 45 shows a structure inwhich one memory device 100 is included in the memory system 20.However, embodiments of the present disclosure are not limited thereto.For example, a plurality of memory devices may be included in the memorysystem 20.

To be specific, the memory device 100 may include a memory cell region1502 for storing data, and generate a modulation clock DCLK including Nmodulation sections by performing a modulation operation on anexternally inputted source clock SCCLK according to a specific scheme.Herein, N may be a natural number equal to or greater than 2. Also, thememory device 100 may output the read data RDDATA that are read from thememory cell region 1502 in synchronization with the modulation clockDCLK.

To be more specific, the memory device 100 may read the read data RDDATAfrom the memory cell region 1502 in response to a read command (notshown) inputted from the controller 200. Also, the memory device 100 maygenerate a modulation clock DCLK including N modulation sections byperforming a modulation operation on the source clock SCCLK according toa specific scheme. Also, the memory device 100 may synchronize the readdata RDDATA with the modulation clock DCLK and output the result to thecontroller 200. Also, the modulation circuit 1504 included in the memorydevice 100 may generate a modulation clock DCLK by performing amodulation operation on the source clock SCCLK according to a specificscheme and output the generated modulation clock DCLK to the controller200. The output circuit 1503 included in the memory device 100 may readthe read data RDDATA from the memory cell region 1502 in synchronizationwith the modulation clock DCLK and output the read data RDDATA to thecontroller 200.

The controller 200 may output the source clock SCCLK to the memorydevice 100, and then receive the read data RDDATA transferred from thememory device 100 in response to the modulation clock DCLK transferredfrom the memory device 100. Also, the controller 200 may verify thereliability of the read data RDDATA corresponding to the N modulationsections that are included in the modulation clock DCLK for eachmodulation section through a demodulation operation according to aspecific scheme.

Herein, the operation of verifying the reliability of the read dataRDDATA in the controller 200 may include an operation of verifyingwhether abnormal data are included in the read data RDDATA inputtedthrough the input circuit 1302. In other words, the controller 200 maydivide the modulation clock DCLK into N modulation sections through ademodulation operation based on a specific scheme, and verify whetherthere are abnormal section data among the N section data (not shown)included in the read data RDDATA and respectively corresponding to the Nmodulation sections in the modulation clock DCLK.

To be more specific, the clock generator 1301 included in the controller200 may generate a source clock SCCLK. The modulation circuit 1504included in the memory device 100 may receive the source clock SCCLKgenerated by the clock generator 1301, perform a modulation operation onthe source clock SCCLK according to a specific scheme so as to generatethe modulation clock DCLK including the N modulation sections, andoutput the modulation clock DCLK to the controller 200. In anembodiment, the modulation circuit 1504 is implemented to include afrequency modulation circuit. For example, the modulation circuit 1504includes a frequency modulator that receives a DC input and generatesthe modulation signal DCLK in response to the DC input by varying avalue of the DC input to generate the N modulation sections of themodulation signal DCLK having different frequencies. The output circuit1503 included in the memory device 100 may output the read data RDDATAto the controller 200 in response to the modulation clock DCLK. Theinput circuit 1302 included in the controller 200 may receive the readdata RDDATA transferred from the memory device 100 in response to themodulation clock DCLK transferred from the memory device 100. Also, theverification circuit 1305 included in the controller 200 may perform ademodulation operation on the modulation clock DCLK according to aspecific scheme, and verify the reliability of the read data RDDATAcorresponding to the N modulation sections included in the modulationclock DCLK for each modulation section.

The internal circuit 1303 included in the controller 200 may perform anoperation for securing the reliability of the read data RDDATA inputtedthrough the input circuit 1302 based on the verification informationVRINFO outputted from the verification circuit 1305, and then use theread data RDDATA inputted through the input circuit 1302 according to apredetermined purpose.

Herein, the operation for securing the reliability of the read dataRDDATA inputted through the input circuit 1302 may be an operation forrequesting the memory device 100 to selectively re-read and output onlyabnormal section data among N section data included in the read dataRDDATA respectively corresponding to the N modulation sections includedin the modulation clock DCLK. In other words, when it is assumed thatthe read data RDDATA have a predetermined size, the operation may be anoperation for requesting the memory device 100 to re-read only somesection data that are abnormal among the N section data included in theread data RDDATA. For example, although not illustrated in detail in thedrawing, the internal circuit 1303 may generate a read command forselectively re-reading abnormal section data and transfer the readcommand to the memory device 100. Subsequently, when some section datathat are requested to be re-read are transferred to the controller 200and the reliability of the section data is verified by the verificationcircuit 1305, the internal circuit 1303 may use the read data RDDATAincluding the section data that are re-read for a predetermined purpose.For example, referring back to FIG. 42, the internal circuit 1303 mayperform an operation for outputting read data RDDATA to the host 102communicating with the host interface unit 132 and the processor 134.

Meanwhile, FIGS. 45, 46, and 47 may be referred to in order to describea modulation operation and a demodulation operation based on a specificscheme.

First, referring to FIGS. 45 and 46, the modulation operation and thedemodulation operation based on the specific scheme may refer tofrequency modulation and frequency demodulation, respectively. In otherwords, the modulation operation based on the specific scheme may mean amodulation operation using N different frequencies. Herein, it isassumed that N is a natural number equal to or greater than 2, and it isassumed in FIG. 46 that N is 4.

To be specific, for example, the source clock SCCLK generated by theclock generator 1301 of the controller 200 may have a substantiallyuniform frequency.

The modulation circuit 1504 included in the memory device 100 mayperform a frequency modulation operation of modulating the frequency ofthe source clock SCCLK inputted from the controller 200 to generate themodulation clock DCLK that is divided into four modulation sections A,B, C, and D. The four modulation sections A, B, C, and D included in themodulation clock DCLK may be detected according to their frequencydifferences. For example, the section D of the four modulation sectionsincluded in the modulation clock DCLK may have substantially the samefrequency as the source clock SCCLK, and the section C may have a lowerfrequency than the section D, and the section B may have a lowerfrequency than the section C, and the section A may have a lowerfrequency than the section B.

The output circuit 1503 included in the memory device 100 may output theread data RDDATA read from the memory cell region 1502 insynchronization with the respective four modulation sections A, B, C,and D included in the modulation clock DCLK. Therefore, the value of theread data RDDATA may be determined according to each of the fourmodulation sections A, B, C, and D included in the modulation clockDCLK. For example, it may be assumed that the memory device 100 is aNAND flash memory and the read data RDDATA have a data sizecorresponding to four pages. In this case, a first portion of the readdata RDDATA read from the first page (not shown) of the memory cellregion 1502 included in the memory device 100 may be first section datathat are synchronized with the section A among the four modulationsections A, B, C, and D included in the modulation clock DCLK. A secondportion of the read data RDDATA read from the second page (not shown)may be second section data that are synchronized with the section B. Athird portion of the read data RDDATA read from the third page (notshown) may be third section data that are synchronized with the sectionC. A fourth portion of the read data RDDATA read from the fourth page(not shown) may be fourth section data that are synchronized with thesection D.

To sum up, the read data RDDATA may include the first to fourth sectiondata. Also, the first to fourth section data included in the read dataRDDATA may be respectively synchronized with the four modulationsections A, B, C, and D included in the modulation clock DCLK. Herein,since the four modulation sections A, B, C, and D included in themodulation clock DCLK have different frequencies, the first to fourthsection data included in the read data RDDATA may be synchronized withclocks of different frequencies, respectively.

The input circuit 1302 included in the controller 200 may receive theread data RDDATA transferred from the memory device 100 in response tothe modulation clock DCLK transferred from the memory device 100.

The verification circuit 1305 included in the controller 200 may performa frequency demodulation operation on the modulation clock DCLKtransferred from the memory device 100, thereby providing fourmodulation sections A, B, C, and D. In other words, the verificationcircuit 1305 may detect a change in frequency by performing a frequencydemodulation operation onto the modulation clock DCLK so as to produce afrequency change detection result. Based on the frequency changedetection result, the four consecutive modulation sections A, B, C, andD that are included in the modulation clock DCLK may be distinguished.As such, the verification circuit 1305 may be able to detect the firstto fourth section data that are included in the read data RDDATA throughan operation of detecting the four consecutive modulation sections A, B,C, and D included in the modulation clock DCLK. To be specific, theverification circuit 1305 may detect a first portion of the read dataRDDATA corresponding to the section A among the four consecutivemodulation sections A, B, C, and D included in the modulation clock DCLKas the first section data, detect a second portion of the read dataRDDATA corresponding to the section B as the second section data, detecta third portion of the read data RDDATA corresponding to the section Cas the third section data, and detect a fourth portion of the read dataRDDATA corresponding to the section D as the fourth section data.

Also, the verification circuit 1305 may be able to verify thereliability of the read data RDDATA for each modulation section bydetecting the first to fourth section data included in the read dataRDDATA. In other words, the verification circuit 1305 may be able toindependently verify whether each of the first to fourth section dataincluded in the read data RDDATA is in a normal state or not.

For example, some bits included in the second section data among thefirst to fourth section data included in the read data RDDATA may belost in the process of being transferred from the memory device 100 tothe controller 200.

In this case, the verification circuit 1305 may be able to verify thatsome bits of the second section data are missing among the first tofourth section data included in the read data RDDATA and thus the secondsection data are not in a normal state. Of course, the verificationcircuit 1305 may be able to verify that the remaining section data,i.e., the first, third and fourth section data, are in a normal state.The verification circuit 1305 may generate verification informationVRINFO that represents the result verifying that the second section dataare not in a normal state while the remaining first, third, and fourthsection data are in a normal state, and output the generatedverification information VRINFO to the internal circuit 1303.

Accordingly, the internal circuit 1303 may determine that the secondsection data among the first to fourth section data included in the readdata RDDATA are not in a normal state based on the verificationinformation VRINFO outputted from the verification circuit 1305.Subsequently, the internal circuit 1303 may request the memory device100 to selectively re-read and output only the second section data fromthe memory cell region 1502. For example, the internal circuit 1303 maygenerate a read command (not shown) for selectively re-reading only thesecond section data and transfer the read command to the memory device100.

Herein, the internal circuit 1303 may stop the frequency modulationoperation of the modulation circuit 1504 included in the memory device100 and the frequency demodulation operation of the verification circuit1305 included in the controller 200 from the moment when it requests thememory device 100 to perform the re-read operation until the re-readoperation is complete.

To be specific, the internal circuit 1303 may generate an operationselection signal OPC having the first value when the internal circuit1303 requests the memory device 100 to re-read the second section data,and then transfer the generated operation selection signal OPC to themodulation circuit 1504 and the verification circuit 1305. Herein, themodulation circuit 1504 included in the memory device 100 may stopperforming the frequency modulation operation in response to theoperation selection signal OPC having the first value transferred fromthe internal circuit 1303. Also, the verification circuit 1305 may stopperforming the frequency demodulation operation in response to theoperation selection signal OPC having the first value transferred fromthe internal circuit 1303.

Herein, since the modulation circuit 1504 has stopped the frequencymodulation operation, the modulation circuit 1504 included in the memorydevice 100 may transfer the source clock SCCLK generated by the clockgenerator 1301 included in the controller 200 back to the controller200. To be specific, the modulation circuit 1504 included in the memorydevice 100 may transfer the source clock SCCLK from the controller 200to the output circuit 1503 included in the memory device 100 and thecontroller 200. Accordingly, the output circuit 1503 may output thesecond section data re-read from the memory cell region 1502 to thecontroller 200 in synchronization with the source clock SCCLK.

Also, the input circuit 1302 included in the controller 200 may receivethe second section data that are re-read from the memory device 100 inresponse to the source clock SCCLK which is transferred from the memorydevice 100.

The verification circuit 1305 included in the controller 200 may verifyagain whether the second section data re-read from the memory device 100are in a normal state or not. Herein, the verification circuit 1305 maykeep stopping the frequency demodulation operation since the moment whenthe modulation circuit 1504 stops the frequency modulation operation.Therefore, the verification circuit 1305 may verify whether the secondsection data transferred from the memory device 100 are in a normalstate or not in response to the source clock SCCLK.

As a result of verifying the second section data transferred from thememory device 100 in the verification circuit 1305, when it turns outthat the second section data are in a normal state, verificationinformation VRINFO indicating that the second section data are in anormal state may be generated and outputted to the internal circuit1303. Accordingly, the internal circuit 1303 may combine the secondsection data that are re-read and verified to be in a normal state withthe first, third, and fourth section data that are previously read andverified to be in a normal state. As a result, the internal circuit 1303may receive the read data RDDATA whose first to fourth section data areall verified to be in a normal state. Therefore, the internal circuit1303 may be able to use the read data RDDATA whose first to fourthsection data included therein are all verified to be in a normal stateaccording to a predetermined purpose. Also, the internal circuit 1303may generate an operation selection signal OPC having a second valuewhen the read data RDDATA which is verified to have all the first tofourth section data in a normal state and transfer the generatedoperation selection signal OPC to the modulation circuit 1504 includedin the memory device 100 and the verification circuit 1305 included inthe controller 200. Herein, the modulation circuit 1504 included in thememory device 100 may resume performing the frequency modulationoperation in response to the operation selection signal OPC having thesecond value transferred from the internal circuit 1303. Also, theverification circuit 1305 included in the controller 200 may resumeperforming the frequency demodulation operation in response to theoperation selection signal OPC having the second value transferred fromthe internal circuit 1303.

Herein, although the operation selection signal OPC is illustrated asbeing directly inputted to the modulation circuit 1504 included in thememory device 100, this is because the drawing is briefly illustrated tofacilitate understanding of embodiments of the present disclosure.However, embodiments of the present disclosure are not limited thereto.For example, the operation selection signal OPC generated by theinternal circuit 1303 may be transferred to the modulation circuit 1504included in the memory device 100 in a form that the operation selectionsignal OPC is included in a particular command transferred from thecontroller 200 to the memory device 100.

As a result of re-verifying the second section data transferred from thememory device 100 in the verification circuit 1305, when the secondsection data are still in an abnormal state, verification informationVRINFO indicating that the second section data are in an abnormal stateis re-generated and outputted to the internal circuit 1303. In thiscase, the internal circuit 1303 may attempt a repetitive read operationof requesting the memory device 100 to selectively re-read and outputthe second section data, and may attempt a recovery operation ofrecovering the abnormal second section data into a normal state throughan error correction code unit (e.g., the error correction code unit 138in FIG. 42) that may be included therein. Herein, which operationbetween the repetitive read operation and the recovery operation is tobe performed in the internal circuit 1303 may be predetermined accordingto a designer's selection.

Referring to FIGS. 45 and 47, the modulation operation and thedemodulation operation based on a specific scheme may mean phasemodulation and phase demodulation, respectively. In short, themodulation operation based on a specific scheme may mean a modulationoperation using N different phases. Herein, it is assumed that N is anatural number equal to or greater than 2 and it is assumed in FIG. 47that N is 4.

To be specific, for example, it may be regarded that the phase of thesource clock SCCLK generated in the clock generator 1301 of thecontroller 200 has a reference phase.

The modulation circuit 1504 included in the memory device 100 maygenerate a modulation clock DCLK that is divided into four phasemodulation operations A, B, C, and D by performing a phase modulationoperation of modulating the phase of the source clock SCCLK inputtedfrom the controller 200. Herein, the four modulation sections A, B, C,and D included in the modulation clock DCLK may be detected according totheir phase differences. For example, the section A among the fourmodulation sections included in the modulation clock DCLK may have aphase difference of P1 with respect to the source clock SCCLK, thesection B may have a phase difference of P2 with respect to the sourceclock SCCLK, the section C may have a phase difference of P3 withrespect to the source clock SCCLK, and the section D may have a phasedifference of P4 with respect to the source clock SCCLK. In anembodiment, P1, P2, P3, and P4 may be approximately 45 degrees, 135degrees, 225 degrees, and 315 degrees, respectively.

To sum up, the modulation operation and the demodulation operation basedon a specific scheme may refer to frequency modulation and frequencydemodulation, respectively, which are described earlier with referenceto FIGS. 45 and 46. Also, the modulation operation and the demodulationoperation based on a specific scheme may refer to phase modulation andphase demodulation, respectively, which are described with reference toFIGS. 45 and 47. As described above, although the modulation operationand the demodulation operation based on a specific scheme may bedifferent from each other, as shown in FIGS. 46 and 47, the controller200 and the memory device 100 of FIG. 45 operate similarly in that afterthe memory device 100 generates the modulation clock DCLK1 including theN modulation sections by performing a modulation operation on the sourceclock SCCLK, the controller 200 receives the read data RDDATAtransferred in a state synchronized to the modulation clock DCLK2 andperforms an operation of verifying the reliability of the read dataRDDATA corresponding to the N modulation sections included in themodulation clock DCLK2 for each modulation section by performing ademodulation operation in the controller 200. Therefore, detaileddescriptions on the operation of the controller 200 and the memorydevice 100 of FIG. 45 based on the scheme of FIG. 47 that are similar tothose described above with reference to FIGS. 45 and 46 may be omittedin the interest of brevity.

According to the embodiment of the present disclosure described above, adata clock may be modulated through a modulation operation based on aspecific scheme to generate a modulated data clock, and verificationinformation for verifying the reliability of the read data RDDATA thatare read from the memory device 100 may be included in the modulateddata clock. Herein, since the read data are synchronized with themodulated data clock and outputted from the memory device 100, theverification information may be detected in the outside of the memorydevice by demodulating the modulated data clock through a demodulationoperation based on a specific scheme. The reliability of the read datamay be verified based on the detected verification information.

According to the embodiments of the present disclosure, verificationinformation for verifying the reliability of read data that are readfrom a memory device may be included in a modulated data clock bymodulating a data clock through a modulation operation based on aspecific scheme and generating a modulated data clock.

Herein, since the read data are outputted from the memory device afterbeing synchronized with the modulated data clock, the verificationinformation may be obtained by demodulating the modulated data clockthrough a demodulation operation based on a specific scheme, and thereliability of the read data may be verified based on the obtainedverification information. For example, a memory system according to anembodiment of the present disclosure may perform a modulation operationon a clock signal to generate a modulation clock signal that includes aplurality of modulation sections. When read data are read insynchronization with the modulation clock signal, the memory systemperforms a demodulation operation on the modulation clock signal todistinguish the plurality of modulation sections in the modulation clocksignal, and thus a plurality of section data of the read datarespectively corresponding to the plurality of modulation sections ofthe modulation clock signal can be distinguished. In other words, thememory system indexes the read data by the plurality of modulationsections of the modulation clock signal that respectively correspond tothe plurality of section data of the read data. When specific sectiondata of the read data includes one or more abnormal bits, the specificsection data may be re-read from a memory cell region, rather thanre-reading the entire read data, thereby increasing the efficiency ofperforming a read operation compared to a conventional memory system.

While the present disclosure has been shown and described with referenceto certain embodiments thereof, it will be understood by those skilledin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the present invention asdefined by the appended claims and their equivalents. Therefore, thescope of the present invention should not be limited to theabove-described embodiments but should be determined by the appendedclaims including equivalents thereof.

In the above-described embodiments, steps may be selectively performedor some steps or portions thereof may be omitted. Steps need notnecessarily be performed in accordance with the described order in allembodiments. The disclosed embodiments are provided to facilitate anunderstanding of the present invention, not to limit it. That is, itshould be apparent to those skilled in the art that variousmodifications can be made on the basis of the technological scope of thepresent disclosure.

Although specific terminologies are used herein, they are used only toexplain the embodiments of the present disclosure. Therefore, thepresent disclosure is not restricted to the above-described embodiments,as those skilled in the art will recognize that many variations arepossible within the spirit and scope of the present disclosure. Thepresent invention encompasses all modifications and variations of anydisclosed embodiment that fall within the scope of the appended claims.

What is claimed is:
 1. A memory controller for controlling a pluralityof memory devices coupled through a plurality of channels, the memorycontroller comprising: a request checker configured to identify memorydevices corresponding to requests received from a host among theplurality of memory devices, and generate device information on theidentified memory devices to perform operations corresponding to therequests; a dummy manager configured to output a request for controllinga dummy pulse to be applied to channels of selected memory devicesaccording to the device information among the plurality of channels; anda dummy pulse generator configured to sequentially apply the dummy pulseto the channels coupled to the selected memory devices based on therequest for controlling the dummy pulse.
 2. The memory controller ofclaim 1, wherein the dummy manager outputs a dummy pulse generationrequest for requesting the dummy pulse to be applied to the channelscoupled to the selected memory devices before the selected memorydevices start.
 3. The memory controller of claim 1, wherein the dummypulse generator applies the dummy pulse to any one channel among thechannels coupled to any one of the selected memory devices according tothe device information.
 4. The memory controller of claim 1, furthercomprising: an enable signal generator configured to generate chipenable signals for selecting the plurality of memory devices; and acommand queue group including command queues respectively correspondingto the plurality of memory devices.
 5. The memory controller of claim 1,wherein the dummy manager receives chip enable signals respectivelycorresponding to the selected memory devices according to the deviceinformation, and determines memory devices to end operations, based onchip enable signals in a high state among the received chip enablesignals.
 6. The memory controller of claim 1, wherein the dummy manageroutputs a command queue level request for determining command queuelevels of memory devices corresponding to chip enable signals in thehigh state, and wherein the command queue group outputs the commandqueue levels corresponding to the command queue level request.
 7. Thememory controller of claim 1, wherein the dummy manager determines toapply the dummy pulse to channels coupled to the memory devicescorresponding to the chip enable signals in the high state.
 8. Thememory controller of claim 1, wherein the dummy manager determines tointerrupt the dummy pulse applied to any one of the channels.
 9. Thememory controller of claim 1, wherein the dummy manager determineswhether a number of memory devices of which command queue levels has avalue is two or more.
 10. The memory controller of claim 1, wherein thedummy manager determines to apply the dummy pulse to the channelscoupled to the memory devices corresponding to chip enable signals in ahigh state and interrupts the dummy pulse applied to channels coupled tothe memory devices of which command queue levels has a value.